NOTICE 컴컴컴 This book is copyright. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electrical, mechanical, photocopying, recording or otherwise without the prior written permission of Charles P. White. Every effort has been made to ensure complete and accurate information concerning the material presented in this book. However, the Author, can neither guarantee nor be held legally responsible for any mistakes in printing or faulty instructions contained in this book. The Author will appreciate receiving any information on this subject, including any errors or misprints. The programs presented in this book are for demonstration and testing purposes only. The Author will take no responsibility nor can be held legally responsible for damages caused by improper handling or use of the demonstration programs. This is the First Edition and First Publication. First released on Shareware Diskette in 1987/88. Regsitration required at 10 uk pounds sterling. Used as a teaching aide: 70 uk pounds sterling. Preface I hope that this book assists you to understand the concepts of Basic Programming a little better. It may be of assistance, if you have already used Basic on another Computer and wish to move over to IBM standards. With this in mind, this book may help to covert some routines from a non standard Basic. This book is for the Beginer and in no way implies a complete coverage of the Basic language. Special thanks to Mr. David Bransfield for giving up his time to do all the prove reading for me. Thankyou David. 1987/88/89/90/91 Reference material used: Using Basic on the IBM PC By : Angela and Michael Trombetta A special thankyou to Angela and Michael Trombetta for a well written book. Charles Peter White November 1987,1988,1989,1990,1991,1992 and 1993 This book is dedicated to my wife Pauline, and daughters, Paule and Christine. 旼컴컴컴컴컴컴컴컴컴� � BASIC'S ASSISTANT � 읕컴컴컴컴컴컴컴컴컴� Written by Charles Peter White 1987-1993 26, Oakdene, Stourport-On-Severn, Worchestershire, DY13 9NF, ENGLAND. (C) Copyright. All Rights Reserved 1987-1993 旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿍asicA/GWBasic/P-Basic/Quick Basic/Turbo/Power.� 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� TurboBasic(r) Borland International Inc. PowerBasic(r) Spectra Publishing. Microsoft(r), and MS-DOS are registered trademarks of Microsoft Corporation. IBM(r) is registered trademark of International Business Machines Limited. 旼컴� � 2 � 읕컴� Introduction This book was written for those of you who really want to program but have found it difficult because of the technical way books have previously been written. You can type in the routines (which are covered with notes on how things work), and see how they operate and what results they produce. I have placed a great deal of emphasis on routines that really work, giving good screen layouts, proper keyboard entry systems ( with error checking for wrong key entry ) and a host of other things. The Basic's Assistant is a quick tutorial for the Beginner and the Intermediate programmer. Basic is referred to as Microsoft's BasicA, TurboBasic, PowerBasic, P-Basic, Basic, GW-Basic and Quick Basic 3.0 to 4.5. These programming languages are generally used for IBM machines and close compatibles, some differences may be found in some machines. MS/PC-DOS is also required to execute the routines in this book. It is suggested that you have the manual [ as supplied with your computer or obtained from a library ] for one of the topics you wish to learn or further your knowledge. BASIC terms will be used in the form of GW-Basic, as this has all the BasicA commands and a few other subtle differences, while Quick Basic will be in both GW-Basic and Quick Basic 3.0 and above [ if possible ]. This book is divided into four main sections, 1) Lets Get going, 2) Reference. This will list out the commands and their meanings, giving you a quick and easy reference, 3) Errors. If you have typed something wrong or the computer states that an error has 旼컴� � 3 � 읕컴� ocurred, this will show what has happened, and finally, 4) USEFUL TIPS. Some tips on how to look at keys, what type of monitor you are using and other functions. For Amstrad users, use P-Basic/Turbo/Power/QB. 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 BASICS and their use 컴컴컴컴컴컴컴컴컴컴 Although Basic is a High Level language and Assembler is a low level one, it should be understood that Basic is very powerful and can do almost anything that assembler can. Only a few points are against Basic as a programming tool. A). Basic is slow because it requires an interpreter to run it, thus slowing the speed down, and only allowing 64,000 bytes to be used 'in full' as the main program. B). Programming is simple and requires little thought, but the finished program can be 'all over the place' without the need for proper structuring and therefore leaving the programmer at a lose when he/she comes to correct or add routines. C). To produce clever effects with scrolling screens, special windows and nice pull-down windows, it takes a lot of thought and a great deal of programming and memory. D). The larger the program the smaller the data files become. HOWEVER...... 旼컴� ...... � 4 � 읕컴� There are many other types of special utilities on the market that will enhance your Basic programs and produce very fast and compact routines that will work efficiently and use memory as machine code does. These Utilities are called Compilers, Basic aids and Basic enhancements. They need not cost the Earth, and will provide the user 'That's you', with most of what you require, with the desired effects. It is best to remember that if you require these special programs/aids, then it is in your interest to make sure that they are compatible with your system and do not require special knowledge to operate them. Most helpful routines should be written in assembler with special code that you can use within your basic programs. Having to adapt them is really a waste of time and money. Always find someone who knows the product and can show you how it works with 'YOU IN MIND'. Always ask questions until you understand, NEVER pretend that you understand, you end up paying for a product that could be the wrong thing for you. You can get some very good products ucts from Shareware at a very small production cost, which in most cases are complete with documentation. The Authors may ask for a small fee, which is in everyone's interest to pay. This encourages the Authors to produce better and better products. The routine TXT2COM is also my early Shareware version. Please remember, that this routine can only be used for private and personal use only. If you use a Bulletin Board to get your software, please check for full documentation and requirements for that product. If anything is missing, report it. 旼컴� � 5 � 읕컴� There are many companies that deal with Shareware and can be found in your computer magazines, and BBS Systems. The production cost will vary from one company to another but is usually between �1.50 to �3.50 per disk. It is in your interest to seek them and get the product lists from them. If you use them, REGISTER them. There is always something of interest. You can get products from a vast array of companies other than Shareware. I have found that top quality products with support cost around 20-80 pounds. This includes registration fees. If you have written something yourself, then why not place your program/s with them for distributing. Remember to place a Copyright notice with your full name and address on all your programs and documentation. Any restrictions on use of your software must be placed within the documentation. 旼컴� � 6 � 읕컴� 旼컴컴� 쿔ndex� 읕컴컴� Introduction 2 Alphabetical Index 216 Functional Index 220 Protect you Copyright Material 230 ANSI Colour Codes 231 ASCII Codes 234 Extended Key Codes 238 LETS GET GOING: Manipulating Strings 10 STRINGS.BAS 10 DATE.BAS 12 INDELOT.BAS 13 LOADER.BAS 21 Read and Data commands: 24 TXT2COM.BAS 25 Peek and Poke Grey keys: 30 PK-BRD.BAS 30 Function keys: FUNKEY1.BAS 33 FUNKEY2.BAS 35 旼컴� � 7 � 읕컴� Using the printer: PRINTER.BAS 38 Reading and Saving data files: 47 ON ERROR and RESUME 49 APPEND 50 WRAP1.BAS 52 Modem/Network Communications Index:: 62 REFERENCE 컴컴컴컴� The direct command from DOS 118 The editor and its commands 120 Similar dos type commands in basic 127 Shortcut keys for the editor 129 Editing keys 130 File handling 132 Error trapping 142 Variables and constants 144 Command structures 147 Data handling 150 Mathematics 153 Screen output 156 Graphics 163 旼컴� � 8 � 읕컴� Getting input from the keyboard 173 String handling 175 Printer output 179 Techniques in using the interrupts 181 Machine code 185 Sound commands 187 Memory accessing 189 I/O communications 192 ERRORS 컴컴컴 Error messages 196 USEFUL TIPS 205 컴컴컴컴컴� Special keys 206 Monitor type 206 Memory (RAM) 206 DOS keyboard fonts 206 Screen locations & DEMO program 207 Dis/Enable Keyboard 210 Check for various devices .BAS 210 COMMAND$ Line Switching 212 旼컴커 � 10 � 읕컴켸 旼컴컴컴컴컴컴컴� 쿗et's Get Going� 읕컴컴컴컴컴컴컴� After you type in a program, SAVE it before testing. Load in your Basic interpreter by following its manual. Manipulating strings: First we shall have a look at string handling. How to examine a string by splitting it up and printing the results. STRINGS.BAS: 1 A$="ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMN OPQRSTUVWXYZ1234567890123456789012" We first define a string (A$) with some characters. 2 A=LEN(A$) We now set a variable (A) to the total numerical LENgth of A$. In this case the length given to (A) will be 72 (characters). 3 CLS Now clear the screen. 4 FOR I=1 TO A We set a loop to start at 1 and end with the value of (A). 5 LOCATE 1,1:PRINT LEFT$(A$,I) Set the cursor to the top of the screen and print the left expression of the string we set up in A$ to the total value of characters as 旼컴커 � 11 � 읕컴켸 determined by the value in 'I'. So, if 'I' =1 then the first character will be printed. If 'I' is 2, both first and second characters will be printed, and so on. 6 LOCATE 3,1:PRINT MID$(A$,I,1) Set the cursor to the third line from the top and print only one character according to the value of 'I'. The (A$ is the string, I is the position in that string we want, 1 is the amount of characters we want). Change 1 to 2 etc; and run the routine to see what you get. Then swap around I and 1. This will give you a very good idea of how the MID$ function works. You could also change LOCATE 3,1 to LOCATE 3,I this will move the character along under the top display. 7 R$=RIGHT$(A$,I):LOCATE 5,1:PRINT R$ There we set R$ as the right most character of the string A$. As 'I' starts with 1 in the loop, the character will be the last, but as 'I' increases its value you will get the last two and so on. Here we are printing backwards, from the last to first. 8 S$=RIGHT$(A$,A-I):LOCATE 7,1:PRINT S$;" " The string S$ is set to the right most character of string a$, but with a formula of A-I. 'A' is set as the total length of A$, while 'I' starts with one in the loop. Therefore, as 'I' increases its value it is subtracted from 'A' which gives the result of the characters we want to see. If I=2 then the result will be a total of 70 (A=72, I=2, 72-2=70). What we are doing here is to look at a chunk starting with the complete string (A$) and 旼컴커 � 12 � 읕컴켸 moving along one letter at a time to the right, Still looking and displaying the balance of A$. 9 FOR T=1 TO 500:NEXT This is a delay loop so that you can see what is happening. 10 NEXT Continues the FOR I loop. When 'I' has reached the same value as 'A' then the loop finishes. That concludes this routine. DATE.BAS 컴컴컴컴 Here's a quick routine you can use to include in any program to give the correct dates form the year 100. 10 CLS:INPUT "DAY, MONTH, YEAR(SEPERATE WITH COMMAS)";DD,MM,YY 20 IF YY<100 THEN YY=YY+1900 30 IF MM>2 THEN 50 40 MM=MM+12:YY=YY-1 50 N=DD+2*MM+INT(.6*(MM+1))+YY+INT(YY/4)-INT(YY /100)+INT(YY/400)+2:N=INT((N/7-INT(N/7))*7+.5) 60 FOR A=0 TO 6:READ N$(A):NEXT:PRINT N$(N):END 70 DATA "SATURDAT","SUNDAY","MONDAY","TUESDAY" ,"WEDNESDAY","THURSDAY","FRIDAY" You could modify it to read the system time first, then compare the date placed by the user and give the necessary responce. Let us continue with a routine that will allow you to use the INKEY$, RIGHT$, MID$, CHR$() commands, read the keyboard, select special keys or not, insert/over type text. Move 旼컴커 � 13 � 읕컴켸 HOME/END of a line and a host of other nice facilities. It is a short program to type in. This routine is called INDELOT- [ insert/delete/over type ]. INDELOT.BAS: FUNCTION KEYS Control/O Over types old characters with new ones. F1 Clear line F2 Display original text F5 Save new text in another string F9 Re-display the newly saved text Home Cursor to the beginning of text line End Cursor to the end of text line Del Delete character under cursor [ move the rest of the text on the right of the cursor, one place to the left ]. <-Del Delete a character one position to the left of the cursor. By default, this routine is in Insert mode. As you type, any characters to the right of cursor will move over to accommodate the typed character. For test reasons, there is only one line of text which is displayed at the top left of the screen. This enables you to see how text editors work, while not being too complicated to program. Type in the following LINE numbers. Pressing ENTER or RETURN when finished. Do not type in the explanation paragraphs which proceed each line. Your finished program will throw up errors. 旼컴커 � 14 � 읕컴켸 1 A$="This is a test program":B=LEN(A$):PT=B: G$=A$ A$ is the string which we want to print. B is the variable LENgth of the whole string of A$. In this case twenty two characters. PT is a switch variable we use later which shows the current length of the string. G$ is made the same as A$. As it is needed for the RESTORED original text key. 2 CLS:PRINT A$:LOCATE 1,1,1:S=1 CLS clears the screen. PRINT A$ prints the text. LOCATE 1,1,1 places the cursor to the top left of the screen and switches on the cursor (the last 1 in the LOCATE command). S is to count the position of the cursor on that line. 10 R$="":R$=INKEY$:B$=RIGHT$(R$,1):L=LEN(R$) We use R$ for key input as in R$=INKEY$. Special keys that INKEY$ can not get on its own, have to be looked at another way. Normal keys have a single value while others have two. You have to get the right expression of the double figure for those keys. B$ is a check string of the RIGHT$(R$,1). 1 being the far right. L is the variable LENgth of the R$ (key pressed). 25 IF S<=B AND (L=2 AND B$="M") THEN S=S+1:PY=1:GOSUB 150:GOSUB 100:GOTO 10 If the cursor position (S) is less than or equals to the total length of the whole string (B) and the right cursor key was pressed, then ADD 1 to cursor position ( IN S ) ready to move it to the right. PY is a switch. If set to 1 it will do 旼컴커 � 15 � 읕컴켸 something, If 0 then the routine or command will be avoided. GOSUB 150 and GOSUB 100 are temporary jumps to a routine with a 'RETURN' statement. GOTO 10 is a direct command to GOTO a specified line. 30 IF S>1 AND (L=2 AND B$="K") THEN S=S-1:PY=1:GOSUB 150:GOSUB 100:GOTO 10 If the cursor position (S) is greater than one (the first character) and the key pressed was cursor left, then decrease cursor position by one. Set switch on (PY=1) and do the two subroutines, returning to next command which is GOTO 10 (key input). 32 IF A$<>"" AND (L=2 AND B$="S") THEN B$=LEFT$(A$,S-1):GOSUB 150:A$=B$+C$:GOSUB 120 If the string (A$) is not equal to empty and the key pressed was DEL then set B$ as the LEFT part of the string from the cursor position. Temporary jump to line 150 and RETURN. Having deleted a character, set the new length of A$ by adding B$ with C$ (which is the right side characters of the cursor.) 34 IF A$<>"" AND (S>1 AND R$=CHR$(8)) THEN B$=LEFT$(A$,S-2):S=S-1:C$=RIGHT$(A$ ,B-S):A$=B$+C$:GOSUB 120 If the string (A$) is not equal to empty and the cursor position is greater than one, (the first character), and the key pressed (R$) was <-DEL then set B$ to the left-1 of the cursor position. Subtract cursor position by 1. Set C$ for the characters on the right position of the cursor. Add B$ with C$ to make total of A$. Temporary jump to line 120. 旼컴커 � 16 � 읕컴켸 36 IF L=2 AND B$="O" THEN S=B+1:C$="":GOSUB 120 If an extended key was pressed and it was END then cursor position equals the total length of a$ + 1. The cursor will be displayed one character after the last displayed. Set the string value used for the right part of the text to empty. Temporary jump to line 100 38 IF L=2 AND B$="G" THEN S=1:GOSUB 120 If the extended key pressed was HOME then set cursor position to beginning of line (position 1). Temporary jump to line 120 40 IF XO=0 AND R$=CHR$(15) THEN LOCATE 1,77: PRINT"O/T":XO=1:OT=1:GOSUB 130 XO is a switch which indicates if a key for over-type has been pressed. 0=on 1=off. CHR$(15)= CTRL/O. Place the cursor on the first line at position 77 and print O/T for Over-Type on. Set the XO switch off. OT states that over-type is on, this is used again when the same combination of keys is pressed to switch off over-type mode. Temporary jump to line 130 42 IF XO=1 AND R$=CHR$(15) THEN LOCATE 1,77: PRINT" ":XO=0:OT=0:GOSUB 130 If the XO switch is ON and CTRL/O was pressed then print three spaces on the top line where O/T was displayed. Set both X0 and OT switches OFF ready for use. 44 IF L=2 AND B$=";" THEN H$=G$:A$="":S=1: LOCATE1,1:PRINT SPACE$(B):B=0:LOCATE 1,S If F1 was pressed then save the string into H$ and empty the display string A$. Place the 旼컴커 � 17 � 읕컴켸 cursor at the top line and print spaces to the length of the string as in B. Set B switch to 0, as there is no string characters being displayed. Place the cursor back to the beginning of the line. 46 IF L=2 AND B$="<" THEN A$=H$:GOSUB 72:S=1: GOSUB 120 If F2 was pressed then make the current string (A$) from (H$). Temporary jump to routine line 72. Set the cursor position to the beginning of the line. Temporary jump to 120. 48 IF L=2 AND B$="C" THEN A$=I$:GOSUB72:S=1: GOSUB 120 If F9 key was pressed, place saved text into current display (A$). Temporary jump to sub-routine 72. Set cursor position to beginning of line. Temporary jump to sub-routine 120. 50 IF L=2 AND B$="?" THEN I$=A$:GOSUB 72: GOSUB120 If F5 was pressed then make I$ as a saved string of text from the currently displayed text. Temporary jump to sub-routine 72 and then to 120. 67 IF (S<=B AND OT=1) AND (R$>=CHR$(32) AND R$<=CHR$(126)) THEN GOSUB 155 At this point we are looking at two specific conditions before we can do a procedure. A) If the cursor position (S) is less than or equals to the length of the string (B) and OVER/TYPE (OT) has been selected and 旼컴커 � 18 � 읕컴켸 B) If R$ equals to character 32 (space) and R$ is less than or equals to character 126 (~). Characters from 32 to 126 are only allowed. If these two conditions are met then temporary jump to sub-routine in line 155. Both conditions must be met or we avoid this line. 69 IF (S+C<73 AND OT=0) AND (R$>=CHR$(32 AND R$<=CHR$(126)) THEN A=1:GOSUB 100 Once again there are two sets of conditions that we are looking for. A) If the cursor position plus any characters to the right are less than 73 (total characters per line) and Over/Type is off, and B) If R$ (key input) equals to character 32 (space) and R$ is less than or equal to character 126 (~) then temporary jump to sub-routine 100. Once again, all these condition must be met or this line is avoided. 70 A=0:GOTO 10 The 'A' is a switch: See if you can work out what it is for. 72 LOCATE 1,1:PRINT SPACE$(B):RETURN Locate the cursor to the top of the screen. Print a line of spaces according to the value of B and RETURN to the line that called this sub-routine. 100 IF S=1 AND A=1 THEN C$=RIGHT$(A$,B+1): GOTO110 If the cursor position is on the first position of the line and the switch 'A' is 1 then set C$ 旼컴커 � 19 � 읕컴켸 to WHAT ? 105 B$=LEFT$(A$,S-1):C=LEN(B$):C$=RIGHT$(A$,B-S+1) 110 IF A=1 AND S=1 THEN A$=R$+C$:GOTO 120 Now you should be getting the hang of this. Try to work out what the rest of the program does. 115 IF A=1 THEN A$=B$+R$+C$ 120 IF PY=1 THEN PY=0:GOTO 122 121 LOCATE 1,1:PRINT A$" " 122 B=LEN$(A$):C=LEN(C$) 125 IF A=1 THEN S=S+1 130 LOCATE 1,S:R$="":RETURN 150 IF S<=B THEN C$=RIGHT$(A$,B-S):PT=LEN(C$)+1 151 RETURN 155 B$=LEFT$(A$,S):C=LEN(B$):C$=RIGHT$(A$,B-S) 160 A=1:IF S=1 THEN A$=R$+C$:GOTO 120 162 A$=LEFT$(A$,S-1)+R$+C$:GOTO 120 Now you can see how to get input from the key board and separate it into two different types of selections. For standard keys and for the special keys like F1 etc. How to control keyboard input from allowing any other keys other than the ones you wanted. You have looked at the right part of a string by using the RIGHT$ and the left with LEFT$. 旼컴커 � 20 � 읕컴켸 To find the length of a string, the total number of characters/numbers etc, you have used LEN. If you like this routine, why not try to see if you can make it smaller by altering it. See if you can get other special keys. In this example we have not used the IF..THEN..ELSE conditions, but by a very slight alteration to the program they can be demonstrated. Under line 34 we shall insert another line (35). Type in:- 35 If L=2 then 36 ELSE 40 Then remove both L=2 AND at the beginning of lines 36/37. They should both start with IF B$=. Does that work ? The next routine we will look at uses the FILES command with a combination of what was used before. Also used is then DIM statement, DEF SEG, KEY OFF and PEEK. This routine will display the current directory contents on the screen and allow you to move the cursor around each item as if to select them for processing on. 旼컴커 � 21 � 읕컴켸 LOADER.BAS: FUNCTION KEYS 컴컴컴컴컴 컴컴컴컴컴컴� The cursor keys move you through the displayed directory. Some of the lines are very long. Just keep typing and then press RETURN, ENTER, or <�. 1 CLS:CLEAR:KEY OFF:CLT=PEEK(&H10):IF CLT=48 THEN DEF SEG=&HB000 ELSE DEF SEG=&HB800 First clear the screen. Clear any variables/strings from memory. Turn OFF any pre-defined function keys. Now we look to see what type of monitor we are using. If that value is 48 then we are using a MONO monitor otherwise it's a colour one. 2 LOCATE 1,30:PRINT"DEMO FOR LOADING FILES": C=3:D=1:FILES We use C for the Vertical position and D for the Horizontal position of the cursor. Now read the directory. 3 A=320:IF PEEK(336)=46 THEN A=480:C=4 'A' is set to the actual screen position we want for when we look at it with PEEK. If it is a 'full stop' then we move down one line (160 bytes). Remember that every even number holds the character value, while every odd number holds the colour value. 'C' is then reset to 4. One line further down. 4 FOR I=1 TO 12:B=PEEK(A):C$=C$+CHR$(B): IF PEEK(A)=32 THEN 6 Look at the 12 characters and place them into C$. If one of them is a 32 (space) them goto line 6 旼컴커 � 22 � 읕컴켸 5 B$=B$+CHR$(B) The B$ is made to hold the full character set as displayed on the screen. With the spaces. B$ will be used to replace the inverted display when the cursor keys are used. 6 A=A+2:NEXT As 'A' is the character position (even numbers), we scan the next location to the right. NEXT continues the FOR loop until all 12 have been scanned. 7 LOCATE C,D:COLOR 0,7:PRINT C$:LOCATE 23,1: COLOR 7,0:PRINT "b$= ":LOCATE 23,5:PRINT B$ 8 S$=INKEY$:LL=LEN(S$):T$=RIGHT$(S$,1): IF LL<>2 THEN 8 9 IF T$="M" AND PEEK(A+12)<>32 THEN GOSUB 15: A=A+12:D=D+18:GOTO 4 10 IF T$="K" AND PEEK(A-38)<>32 THEN GOSUB 15: A=A-60:D=D-18:GOTO 4 11 IF T$="P" AND (PEEK(A+136)<>32 AND PEEK(A+136)<>101) THEN GOSUB15:A=A+136: C=C+1:GOTO 4 12 IF T$="H" AND (PEEK(A-182)<>58) AND (PEEK(A-184)<>32) THEN GOSUB15:A=A-184: C=C-1:GOTO 4 14 GOTO 8 15 LOCATE C,D:COLOR 7,0: PRINT C$:C$="":B$="":RETURN INDELOT is designed to be used with a short 旼컴커 � 23 � 읕컴켸 directory. You can specify the type of files wanted by using various formats. ie; FILES ".DOC" FILES ".TXT" See your computer manual for more details. Let us now look at the READ and DATA commands. type in the following:- 1 READ A$:PRINT A$:END 2 DATA "THIS IS A TEST" Only one DATA Statement to read which is easy, but what about more than one? 1 READ A$:IF A$=";" THEN END We read the string A$. If we find a semi-colon then end. 2 PRINT A$ 3 GOTO 1 4 DATA "PETER","PAUL","MARY",";" Using the READ/DATA statements are good, but they can be slow to execute, especially if the data statements are very long. 旼컴커 � 24 � 읕컴켸 READ and DATA Commands 컴컴컴컴컴컴컴컴컴컴컴 These data statements are in the form of strings. Now we look at variables (numbers). 1 READ A:IF A=-1 THEN END The -1 is set to determine the end of the data. 2 PRINT A 3 goto 1 4 DATA 23, 33, 123, 17, -1 You could do a loop, a FOR/NEXT statement. This is alright but requires a little more memory space. A combination of strings and variables in the data statement require some little thought. If you want to, you can read in by doing the following:- 1 READ A$,A:IF A$="," OR A=-1 THEN END 2 PRINT A$,A:GOTO 1 3 DATA "PETER",123,"PAUL",34,"MARY",36,";",-1 旼컴커 � 25 � TXT2COM.BAS: 읕컴켸 The next routine will make all ASCII text files (like BAS, TXT, C, ASM,DOC, and so on) into COM files. Files that will load and run automatically, giving you Paging UP/DOWN, HOME (first page), END (last page), and to PRINT the document onto the printer. The total length of a document to be converted must be less than 65,500 bytes long. The machine code (M/C) is in the form of DATA statements. This is read and placed into a file that you can specify or leave the original name by pressing RETURN. Once the data has been SAVED the original text is added to that code and the file is then closed. The original ASCII text file will not be touched in any way. The now newly created COM file can be loaded to view the text. You can dispense with the original ASCII file if you want to. The new statements used are OPEN filename FOR INPUT (OUTPUT) AS #1, INPUT#1, CLOSE, DEFINT, OPEN FOR RANDOM AS #1, FIELD #1, LSET, PUT#1, SHELL, READ, DEF F, and DATA. 1 CLS:CLOSE:CLEAR:LOCATE 1,7:PRINT"TXT2COM: MAKE ASCII FILES AUTOMATICALLY RUN AND DISPLAY. Vs 1.00":LOCATE 2,25:PRINT"(c) C.P.WHITE 1987-1989":CG$=SPACE$(79) 11 DEFINT A-Z:DEFFNEXT$(S$)= LEFT$(S$,INSTR(S$+".",".")-1) + ".COM": ON ERROR GOTO 281 21 INPUT "Enter your source text file: ";INFILE$ 31 PY=1:OPEN INFILE$ FOR INPUT AS #1 旼컴커 � 26 � 읕컴켸 41 INPUT#1,A$ 51 CLOSE:PY=0 61 OUTFILE$=FNEXT$(INFILE$):PRINT"Enter your program name: ["; outfile$;"]"; 71 INPUT" ",TEMP$:IF LEN(TEMP$)<>0 THEN OUTFILE$=FNEXT$(TEMP$) 81 PY=0:OPEN OUTFILE$ FOR INPUT AS #1 91 INPUT#1,A$:IF A$<>"" THEN LOCATE 5,1:BEEP:PRINT CG$:BEEP:LOCATE 5,1:PRINT"FILE EXISTS: CHANGE NAME![";OUTFILE$;"]";:CLOSE: GOTO 71 101 CLOSE 111 OPEN"XXX.PGM" FOR RANDOM AS #1 LEN=1: FIELD #1,1 AS A$ 121 READ B$:IF B$="," THEN 151 131 BYTE=VAL("&H"+B$):LSET A$=CHR$(BYTE) 141 PUT #1:GOTO 21 151 CLOSE #1 161 OPEN"XX.PGM" FOR RANDOM AS #1 LEN=1: FIELD #1,1,A$ Open a temporary file. 171 B$="1A":BYTE=VAL(&H"+B$):LSETA$=CHR$(BYTE): PUT #1:CLOSE Place the value of two bytes (1A) to the file and close it. 旼컴커 � 27 � 읕컴켸 181 JG$="COPY /B XXX.PGM + " + INFILE$ + " + XX.PGM " + OUTFILE$ Now set the string JG$ to use the DOS copy command. Copy the files xxx.pgm + infile$ + xx.pgm into a file OUTFILE$. 191 SHELL JG$ This now uses the DOS command to copy. 201 SHELL "DEL XXX.PGM" DOS command to delete. 211 SHELL "DEL XX.PGM" 221 CLS:LOCATE 12,35:PRINT"JOB COMPLETED":CLOSE 231 LOCATE 14,30:PRINT"ANOTHER CONVERSION (Y/N)" 241 G$=INKEY$ 251 IF G$="Y" OR G$="y" THEN RUN 261 IF G$="N" OR G$="n" THEN END 271 GOTO 241 281 IF PY=0 AND ERR=53 THEN RESUME 101 If switch PY=0 and the error had a value of 53 291 IF PY=1 AND ERR=53 THEN LOCATE 12,24:PRINT INFILE$;" NOT PRESENT..TRY AGAIN..":FOR U=1 TO 15:BEEP:NEXT:RUN If the switch PY is 1 and the error had a value of 53, then the file that you stated was to be converted was not present. 旼컴커 � 28 � 읕컴켸 301 LOCATE 12,30:PRINT"DEVICE ERROR...TRY AGAIN":FOR U=1 TO 15: BEEP:NEXT:RUN This line prints the error message and re-runs the program. Locate the cursor at vertical tab 12 and horizontal position 30. Print the error message. Do a loop for 15 counts while beeping and then re-run. The next lines hold the data statements for the machine code that will be placed onto the disk/ette. 6000 DATA EB,38,90,9,9,45,6E,64,20,20,20 ,48,6F,6D,65,20,20,20,50,67,55,70,20,20, 20,50,67,44,6E,20,20,20,45,53,43,20,20,20, 50,3D,50,72,69,6E,74,20,44,6F,63,24,0,0,0, 0,0,0,0,0,BE,0,0,BF,0,0,83,3E,34,1,1,74,3, E8,0,1,52,51,53,B9,0,0 6005 DATA 8D,1E,BC,2,8A,17,80,FA,1A,74,6C,83, 6,38,1,1,83,3E,34,1,1,74,4,B4,2,CD,21,43,83, 3E,38,1,50,74,5,80,FA,A,75,DC,83,6,36,1,1, 41,89,E,32,1,83,3E,38,1,50,74,1,47,C7,6,38,1, 0,0,83,F9,17,72,BF,B9,0,0,83,3E,34,1,1,74,B5,B4 6010 DATA 0,CD,16,3C,5A,7C,2,2C,20,3C,1B,74, 77,3C,50,74,46,80,FC,47,74,72,80,FC,51,74,7E, 80,FC,49,74,61,80,FC,4F,74,5,EB,D8,EB,61, 90,80,FA,1A,74,D0,C7,6,34,1,1.0,EB,8,90,83, 3E,36,1,18,76,E6,59,BE,0,0,C7,6,36,1,0,0,BF, 0,0,C7,6,32,1 6015 DATA 0,0,E9,4B,FF,EB,CE,8B,F3,52,B4,2, BA,0,0,CD,17,F6,C4,29,75,13,53,8D,1E,BC,2, 8A,17,80,FA,1A,74,7,B4,5,CD,21,43,EB,F2,5B,5A, 8B,DE,8A,17,EB,A4,EB,31,90,B4,4C,CD,21,EB,AE, 83,3E,34,1,1,74,23,C7,6,34,1,0,0,EB,8C,80,FA, 1A,74,89,C7,6 旼컴커 � 29 � 읕컴켸 6020 DATA 32,1,0,0,E8,3,0,E9,A,FF,B4,0,B0,2, CD,10,E8,4A,0,C3,83,3E,36,1,17,76,9A,51,56, 8B,F7,8B,E,32,1,83,3E,34,1,1,74,3,83,C1,17,C7 ,6,34,1,0,0,2B,F1,83,EB,1,8A,17,83,FF,1,74, A9,80,FA,A,74,2,EB,EF,3B,FE,74,3,4F,EB,E8,5E, 59,C7 6025 DATA 6,32,1,0,0,B9,0,0,83,C3,1,EB,9C,53, 52,B7,0,B6,18,E8,F,0,BA,3,1,B4,9,CD,21,B6,0, E8,3,0,5A,5B,C3,B2,0,B4,2,CD,10,C3,"," There is one thing to be said about this program. The display of the text on to the screen is in teletext mode (printing one character at a time). It may be a bit slow, but it does the job. Printing is done continuously without any form of paging. Therefore, any listing done will print continuously unless the text file that you converted already had page feeds written into it. Lines with more than 80 characters will wrap around the screen onto the next line. If you are producing your own documentation files, it may be a good idea to ensure that they are not more than 78 characters per line. This is because you will have to work out the paging. 旼컴커 � 30 � 읕컴켸 PEEK AND POKE GRAY KEYS: PK-BRD.BAS: The next program listing is for PEEK and POKE. Looking at the keyboard and getting NUM/LOCK and CAPS/LOCK. The program is written in a round-about-way. You should be able to sort it by just having a few DEF SEG statements. You can see the values of other special keys in the section called: 'Useful Tips'. 1 CLS:DEG SEG=(&H40) Clear the screen and set the computer to look at address &H40. 2 A=PEEK(&H17) This the location that the keys like NUM/LOCK are looked at. 3 IF A<>32 OR A<>64 OR A<>96 THEN DEF SEG:LOCATE 1,60:PRINT " NORMAL " Make the condition so that the two keys we are looking at (plus a combination of both) are only allowed. If not, then print at the top of the screen "NORMAL", to show nothing was pressed. 4 IF A=32 THEN DEF SEG:LOCATE1,60: PRINT"NUM/LOCK " If 'A' is NUM/LOCK then end the DEF SEG statement and print the key that was pressed. 5 IF A=64 THEN DEF SEG:LOCATE 1,60: PRINT" CAPS" 6 IF A=96 THEN DEF SEG:LOCATE1,60: PRINT"NUM/LOCK + CAPS" 旼컴커 � 31 � 읕컴켸 11 LOCATE 9,26:PRINT"Select mode to switch on":PRINT We now show a selection menu. 12 LOCATE 11,26:PRINT"1. NUM/LOCK" 13 LOCATE 12,26:PRINT"2. CAPS" 14 LOCATE 13,26:PRINT"3. NUM/LOCK + CAPS" 15 LOCATE 14,26:PRINT"4. nothing (normal)" 16 LOCATE 15,26:PRINT"5. KEYBOARD (press a key first) 17 LOCATE 16,26:PRINT"0. QUIT" Now to input from the keyboard. 18 G$=INKEY$:IF G$="1" THEN DEF SEG=(&H40):POKE &H17,32:GOTO 2 We POKE the value of 32 in address &H17. Switch on NUM/LOCK. 19 IF G$="2" THEN DEF SEG=(&H40):POKE &H17,64:GOTO 2 We POKE 64 for CAPS/LOCK 20 IF G$="3" THEN DEF SEG=(&H40):POKE &H17,96:GOTO 2 We POKE 96 for the combination of both keys. 21 IF G$="4" THEN DEF SEG=($H40):POKE &H17,0:GOTO 2 We set the both keys OFF, back to normal. 旼컴커 � 32 � 읕컴켸 22 IF G$="5" THEN 1 Now we want to have a look at what keys were pressed. To make this work, you must press either NUM/LOCK or CAPS/LOCK or both and then press 5. This way we are now PEEKing (to look for) a key. 23 IF G$="0" THEN END 24 GOTO 18 The next routine is for your use. It will display all the values of the special keys (when you press the key) at the top of the screen. Press the ALT key to properly exit. You may find that the values are somewhat different, depending on the machine you are running on. Change the above program if necessary. 1 CLS:DEF SEG=(&H40) 2 A=PEEK(&H17) 3 DEF SEG:LOCATE 1,1:PRINT " " 4 LOCATE 1,1:PRINT A 6 GOTO 1 旼컴커 � 33 � 읕컴켸 Function keys: 컴컴컴컴컴컴� FUNKEY1.BAS: The next section deals with the function keys. Here, there is a listing that shows you how to program them to prevent certain sequences of keys from being pressed. ALT/CTRL/BREAK which will automatically reboot the computer, and CTRL/BREAK which will halt a program (allowing people to see how your program works). Another listing which sets up the bottom line to display the type of function and the routine itself to perform them. This is used extensively on many programs, giving then a professional touch. The first program demonstrates the protection against pressing unwanted keys. This may not work on earlier versions of Basic, as keys 15 to 19 are used for the 101 keyboard. You may have to upgrade your Basic Interpreter. This is not the case with QB3 to 4.5 1 KEY 15,CHR$(&H8)+CHR$(&H1D):KEY 16,CHR$(&H4)+CHR$(&H38) Key 15 is set for ALT/CTRL and Key 17 for CTRL/ALT 2 KEY 17,CHR$(&H4)+CHR$(&H55):KEY 18,CHR$(&H8)+CHR$(&H53) Key 17 is set for CTRL/.DEL and Key 18 for ALT/.DEL 3 KEY 19,CHR$(&H4)+CHR$(&H46) Key 19 is set for CTRL/BREAK 旼컴커 � 34 � 읕컴켸 4 FOR I=15 TO 19:KEY(I) ON:ON KEY(I) GOSUB 6000:NEXT Do a loop from 15 to 19 switching on the control keys. Then if an error has ocurred (if a sequence of keys was pressed as stated in the function keys 15 to 19), jump to an Error message section. 10 CLS:LOCATE 10,25:PRINT"DEMO to prevent ALT/CTRL/BREAK sequences" Clear the screen. Set cursor to vertical position 10 along line 25 and print our message. 11 LOCATE 12,25:PRINT"PRESS ESC TO END" 12 G$=INKEY$:IF G$=CHR$(27) THEN 14 Get a key and see if is Chr$(27) for the ESC key. 13 GOTO 12 14 FOR I=15 TO 19:KEY(I) OFF:NEXT Switch off the predefined keys, otherwise we will not be able to stop a program by using CTRL/BREAK or re-boot the system with ALT/CTRL/.DEL. You could disable them completely by adding to the KEY(I) OFF with :KEY(I)"". This will clear the predefined statements as in lines 1 to 3. 15 END 6000 RETURN This RETURN is part of the ON KEY(I) statement 旼컴커 � 35 � 읕컴켸 in line 4. If an ERROR had ocurred (when any sequence of keys was pressed, as defined in lines 1 to 3), the routine will jump here and then return to the program. You could have an error message printed here. For example:- 6000 LOCATE 23,1:PRINT"YOU CAN NOT STOP THIS PROGRAM":FOR I=1 TO 10:BEEP:NEXT:LOCATE 23,1:PRINT" ": RETURN PLEASE NOTE !! It is important that you always REM out this routine while you are working on your program. It is possible that, while testing other parts of a program, you may have forgotten to set a key correctly or even an escape key to escape. This will cause you to lose your program, as you will have to reboot the system by turning OFF and ON again. For the final version, just before saving, remove the lines 12 to 14 as these are only for your benefit. This routine is of more use for Compilers. FUNKEY2.BAS: To program the function keys 1 to 10, you can add sequences of control codes to perform things like a SHELL or FILES and so on. The following program will set up the bottom line to display the commands and to activate those commands when a function key is pressed. The maximum length of the displayed character at the bottom for each function, is 6. Let's take a look at the following:- 1 CLS:SCREEN 0,0,0:WIDTH 80:CLEAR:FOR I=1 TO 10:KEY I,"":NEXT 旼컴커 � 36 � 읕컴켸 First clear the screen. Set the screen to the default text screen 0. Set the width to 80 columns. Clear memory space just incase there is anything lurking around. Do a loop from 1 to 10 clearing all the function keys of any previous defined functions. 2 KEY 1,"LIST " Function key, when pressed, will write list to the screen. You can decide which lines to list or just press RETURN, ENTER or <�. 3 KEY 2,"RUN"+CHR$(13) Function key 2 has the command RUN followed by a RETURN. This will (when pressed) make the current program automatically execute without you having to type in RUN followed by return. 4 KEY 3,"LOAD"+CHR$(34) Displays LOAD command with an inverted comer (") ready for you to just type in your program name followed by RETURN, ENTER or <�. 5 KEY 4,"SAVE"+CHR$(34) As above but with the SAVE command. 6 KEY 5,"CONT"+CHR$(13) Continue to execute a program if BREAK was pressed. 7 KEY 6,""+CHR$(34)+"LTP1 " 8 KEY 7,"CLS":FILES"+CHR$(13) This will clear the screen and display the 旼컴커 � 37 � 읕컴켸 current directory. 9 KEY 8,"FILES " 10 KEY 9,"KEY " 11 KEY 10,"SCREEN 0,0,0"+CHR$(13) 12 KEY ON Switches on the display at the bottom of the screen. 旼컴커 � 38 � 읕컴켸 Using the printer 컴컴컴컴컴컴컴컴� Your printer manual should cover all the aspects of your printer. It is worth remembering that PRINT prints to the screen, PRINT # file number, will to a drive, while LPRINT will print to the printer. The TAB() command in Basics shifts the character/s to be printed to the numeric expression given in the brackets. However, the characters printed before are not removed, unlike printing on the screen. You should use the command given in your manual rather than any other. Use your printer manual to understand how the printer works and then try some little routines. As an example, you could change the PRINT statement in these listings to LPRINT and see what happens. Following your printer manual, add other commands to change the script and tabulations. PRINTER.BAS: This next program will allow you to select the type of font you want, and then after typing some text and pressing RETURN, will print to the printer. Type in only the line numbers and their text. Remember not to type the comments. 1 CLS:CLEAR:ON ERROR GOTO 67 Clear the screen. If an error occurs, then goto our error routine. The next lines set up strings for printer font types. Have a look at 旼컴커 � 39 � 읕컴켸 your own printer manual and compare the CHR$() statements to what they are. 2 SMALL$ = CHR$(15):UNSMALL$ = CHR$(18):EXPAND.SMALL$ = CHR$(14) + CHR$(15) 3 CANX.EXP.COMP$ = CHR$(18) + CHR$(20):EXPAND$ = CHR$(14) 4 EXPAND.END$ = CHR$(20):DARK$ = CHR$(27) + CHR$(69) 5 ITALIC$ = CHR$(27) + CHR$(52) 6 ITALIC.EXP.CON$ = CHR$(14) + CHR$(15) + CHR$(27) + CHR$(52) 7 ITALIC.EXP$ = CHR$(27) + CHR$(52) + CHR$(14):END.ITALIC$ = CHR$(27) + CHR$(53) 8 START.ULINE$ = CHR$(27) + CHR$(45) + CHR$(1):END.ULINE$ = CHR$(27) + CHR$(45) + CHR$(0) 9 PERM.EXPAN$ = CHR$(27) + CHR$(87) + CHR$(1):END.PERMEXP$ = CHR$(27) + CHR$(87) + CHR$(0) 10 START.DSTRIKE$ = CHR$(27) + CHR$(71):END.DSTRIKE$ = CHR$(27) + CHR$(72) 11 TINYLINE$ = CHR$(27) + CHR$(83) + CHR$(0):END.TINY$ = CHR$(27) + CHR$(84):ESC$ = CHR$(27):CLEANUP$ = CHR$(27) + CHR$(64) 13 WIDTH "LPT1:",80 We set up the printer width to 80 columns using printer device port LPT1. 旼컴커 � 40 � 읕컴켸 14 LPRINT CLEANUP$; Set the printer. 15 CLS:DIM A$(60) Clear the screen. Dimension the A$ to not more than 60 items per line. A$(1) could have "Dear Sir". A$(2) could have "HI !" and so on. Now set out on the screen the selection menu. 16 LOCATE 2,25:PRINT "SELECT PRINT SIZE AND STYLE" 17 LOCATE 4,20:PRINT " PRINT SIZE SELECTION" 18 LOCATE 5,20:PRINT " ========== ==========" 19 LOCATE 7,20:PRINT "10 PITCH ITALICS 1" 20 LOCATE 9,20:PRINT "10 PITCH EMPHASIZED 2" 21 LOCATE 11,20:PRINT "10 PITCH TINYPRINT 3" 22 LOCATE 13,20:PRINT "CONDENSED EXPANDED 4" 23 LOCATE 15,20:PRINT "ITALICS EXPANDED 5" 24 LOCATE 17,20:PRINT "EXPANDED DOUBLE-STRIKE 6" 旼컴커 � 41 � 읕컴켸 25 G$=INKEY$:IF G$<"1" OR G$>"6" THEN 25 Using the INKEY$ function, we set G$ as out input key. Check that only selections from 1 to 6 are valid. If not, repeat input. 26 G=VAL(G$) As we want a numeric expression (ie; 1, 2, 3 etc) to work on, we look at the VALue of G$ and place it in 'G'. 27 LOCATE 19,25:INPUT "DESIRED LEFT MARGIN ",M! Set the cursor on line 19, character position 29 along the screen and request an INPUT for a margin on the left side. If you want to start typing with a margin of 5, then type 5 and press RETURN. 28 ON G GOSUB 31,34,39,42,46,50 Here we use the ON variable GOSUB statement. Depending on the value of 'G', the routine will execute a subroutine. If 'G=3', then third expression on the GOSUB will be executed (38). Having executed a routine, the GOSUB command always returns to the next statement after that command. In this case it's a new line number (as below). The subroutines are to setup strings for the type of print fonts required. 29 GOTO 52 Now we move on to set up the screen display and get the input to be printed on the printer. 31 WIDTH "LPT1:",80 Set the width of printing to 80 columns. 旼컴커 � 42 � 읕컴켸 32 LPRINT CLEANUP$ + ITALIC$ + DARK$ Printout in 10 pitched ITALICS form. 33 RETURN This a subroutine, so RETURN to the caller. 35 WIDTH "LPT1:",80 Set the column width to 80. 36 LPRINT CLEANUP$ + DARK$ Printout in 10 pitched EMPHASIZED form. 37 RETURN This is a subroutine, so RETURN to the caller. 39 LPRINT CLEANUP$ + TINYLINE$ Printout in 10 pitch TINYPRINT. 40 RETURN Return to caller. 42 WIDTH "LPT1:",80 Set column width to 80. 43 LPRINT CLEANUP$ + CHR$(27) CHR$(87) + CHR$(1) + EXPAND.SMALL$ + DARK$ Printout in CONDENSED and EXPANDED form. 44 RETURN Return to caller. 旼컴커 � 43 � 읕컴켸 46 WIDTH "LPT1:",80 Set to 80 columns. 47 LPRINT CLEANUP$ + CHR$(27) CHR$(87) + CHR$(1) + ITALIC.EXP.CON$ + DARK$ Printout in ITALICS + EXPANDED + CONDENSED + EMPHASIZED form. 48 RETURN Return to caller. 50 LPRINT CLEANUP$ + CHR$(27) CHR$(87) + CHR$(1) + START.DSTRIKE$ Printout in EXPANDED and DOUBLE STRIKE form. 51 RETURN Return to caller. Below we have the screen layout and the input routine for the text to be printed. 52 CLS:LOCATE 25,20 Clear the screen and place the cursor in line 25, character position 20. 55 PRINT "WHEN FINISHED TYPING, USE CTRL/BREAK"; 57 LOCATE 1,10 Place cursor in line 1, character position 10 and print the three 旼컴커 � 44 � 읕컴켸 following lines:- 58 PRINT"1234567890123456789012345678901234 5678901234567890123456789012345678901234567 89" 59 PRINT "0--------1---------2---------3---- -----4---------5---------6---------7------ ---8"; 60 PRINT 61 FOR I = 1 TO 55:PRINT TAB( M! - 2)I; Now we setup a loop to run for 55 lines. We print a TAB(Margin-2) with the line count 'I'. Remember you were asked what margin you required. 62 LINE INPUT A$(I) Now we use the LINE INPUT command. This allows you to type in along a line as specified by locate or the last print command. As the loop starts with 1, the first line is A$(1). Once the text has been entered and ENTER pressed we do the following:- 63 LPRINT TAB( M!);A$(I):NEXT Print to the printer at the margin given, our text in A$(I). Then the NEXT statement tells the FOR to increment by 1 and repeat the process until 55 times has been reached. Then we process the next line. 旼컴커 � 45 � 읕컴켸 64 CLS:LOCATE 10,20:PRINT "END OF THE PAGE" Clear the screen. Place the cursor on line 10 at character position 20 and print the text. 65 FOR I = 1 T1O 6000:NEXT:RUN This is a delay loop to 6000. Then the program re-runs. Line 67, 69 and 69 are for ERROR trapping. This is called upon when an error occurred while trying to print to the printer. This is set in line 1. The Statement is ON ERROR GOTO 67. 67 IF ERR = 24 THEN 70 ELSE 68 If the ERR code was 24 (Device timeout) then goto line 70 which tells us there has been an error, otherwise goto to line 68. 68 IF ERR = 25 THEN 70 ELSE 69 If the ERR code was 25 (Device fault) then goto line 70 and so on. 69 ON ERROR GOTO 0 As we have not protected for all errors, the ON ERROR GOTO 0, allows the routine to continue at the point from where the error ocurred. In this case, the routine will wait until you sort things out and press a key. 70 BEEP:BEEP:LOCATE 25,1:PRINT SPC(79):LOCATE 25,20 Sound twice a warning note. Put the cursor on line 25 and print 79 spaces to clear that line. 旼컴커 � 46 � 읕컴켸 Then re-locate the cursor on the same line but a character position 20 and print the text below. 71 PRINT "PRINTER ERROR - RESET and PRESS A KEY" 72 IF INKEY$ = "" THEN 72 Check if a key has been pressed, if not, keep looking until one has. 73 RESUME When using error trapping, a RESUME must be used. Therefore, we resume to where the fault ocurred in a line number. 74 END The end of the program. 旼컴커 � 47 � 읕컴켸 Reading and Saving data files 컴컴컴컴컴컴컴컴컴컴컴컴컴컴� To read a file you start with the OPEN "drive:\path\filename" FOR INPUT AS #1. The drive and path are optional. Then to INPUT #1,A$ or the string/variable or combination you saved in the first place. Let us look at the small routine below. 1 A$="This is a test line that we want to save" The A$ has been assigned some text that we want to deal with. 2 OPEN "TEST.FIL" FOR OUTPUT AS #1 We open a file name "TEST.FIL" to save to. 3 PRINT #1,A$:CLOSE We print the string A$ to that file and then close it. To read the file back again you have to use the following:- OPEN "TEST.FIL" FOR INPUT AS #1 Now to read in what we have just saved. 4 OPEN "TEST.FIL" FOR INPUT AS #1 5 INPUT #1,A$:PRINT A$:CLOSE What happens when we have a file that has a total number of accounts which could change from time to time. How do we load it without having to know how many records there are in that file? 旼컴커 � 48 � 읕컴켸 There are many ways to do this. A simple suggestion would be to place names in a string array. Remember that if you exceed 9 in the brackets then you will have to use the DIM A$() expression. 1 A$(1)="peter":A$(2)="paul":A$(3)="MARY":B=3 Let us assume that we have typed in three names and each time we have typed in a name, the 'B' variable has increased by one. The result is 3. You could have line one say INPUT A$(1):INPUT A$(2):INPUT A$(3) and type in your own names. 2 OPEN "TEST2.FIL" FOR OUTPUT AS #1 3 PRINT #1,B:FOR I=1 TO B:PRINT #1,A$(I):NEXT:CLOSE First we save the total amount of records in that file. Then we do a loop to that value ( as in B ). Print each record and close. Now to READ that file and display the contents. 5 OPEN "TEST2.FIL" FOR INPUT AS #1 6 INPUT #1,B:FOR I=1 TO B:INPUT A$(I):PRINT A$(I):NEXT 7 CLOSE What happens if there are no records or the actual file is not present ? Then we have to use:- 旼컴커 � 49 � 읕컴켸 ON ERROR and RESUME 컴컴컴컴컴컴컴컴컴� For this we should use the ON ERROR GOSUB statement at the beginning of the routine. Place an error routine at the end of the program which will tell it what to do. 1 ON ERROR GOSUB 6000 If an error ocurrs then gosub to the error handling line 6000. 2 OPEN "TEST3.FIL" FOR INPUT AS #1 The TEST3.FIL in this case does not exist, as we have not written a program to create it. 3 INPUT #1,B:FOR I=1 TO B:INPUT #1,A$(I):PRINT A$(I):NEXT 4 CLOSE 5 END 6000 RESUME 4 As the file does not exist, an error ocurred. We told the program to direct the error to line 6000. In this case we RESUMED to close the file and end. We could easily have checked for a specified error code and then printed a message. For example:- 6000 IF ERR = 53 THEN LOCATE 23,1:PRINT"FILE NOT FOUND" You could add other commands to the line like 'press a key' etc and then RESUME 4 Remember that a RESUME must return to the 旼컴커 � 50 � 읕컴켸 routine that caused the error and not to any other part of the program. Serious problems will occur. For the error codes see error messages on page 196. The ON ERROR can be used to debug a program. To see what error had ocurred just place in line 6000 PRINT ERR:END and then look up the codes. On the other hand, if you also want to see where the error ocurred in a line then do the following:- 6000 PRINT ERL;" CODE: ";ERR:END APPEND ------ To add items to a file, we use the APPEND command. 1 INPUT " ENTER TEXT ";A$ 2 OPEN "TEST.TXT" FOR APPEND AS #1 3 WRITE #1,A$ 4 CLOSE:GOTO 1 When finished, use CTRL-Break to stop this when entering a name. Run this routine and type the following:- THIS IS LINE ONE (press ENTER) THIS IS LINE TWO (press ENTER) Once you have finished, have a look at the TEST.TXT file and see the result. Type SHELL (without a line number) and you will be placed in DOS. NB!! Quick Basic users will have to select from the FILE menu: D or S depending on the version they have. Type TYPE TEST.TXT and press ENTER. You should see the two lines you typed in. Now 旼컴커 � 51 � 읕컴켸 type EXIT (press ENTER), and you will be returned to your Basic Interpreter. Run the routine again. Now type THIS IS LINE THREE (press ENTER) Stop the routine with CTRL-Break and SHELL to DOS. Look again at the TEST.TXT file. The new line that you have typed in will be APPENDED to the last line. If you use this routine for displaying documentation, Please place in that file that you used this routine and from where it came from. This routine is Copyright, All rights reserved. You can get the updated version from Shareware under the name FL2COM45. This includes a TSR version with remove. 旼컴커 � 52 � 읕컴켸 WRAP1.BAS 컴컴컴컴� Wrap1 converts a Documentation file that has over 78 characters per line and places larger lines onto the next line, indenting it automatically to the same start as the previous line. The maximum line length is 230 characters while Graphic BOXES (over 78 characters) will have to be manually changed BEFORE running this routine. 1 CLS : CLOSE : CLEAR : LOCATE 1,1: PRINT "Part of the REM series: WRAP 1.0(C)All Rights Reserved. C.P. White 1987-90" First clear the screen. Close any files or devices that were left open. Clear out memory, removes any variables/strings that were assigned etc. Place the cursor on the top line (left) starting a position one. Now print the copyright notice. 2 PRINT:PRINT" Convert ASCII files to less than 78 Characters per line.":PRINT Print two lines some text and then print a blank line. 3 ON ERROR GOTO 11 If an ERROR occurs during processing, GOTO line 11 which handles this. 4 INPUT " Name + Ext (ENTER=Quit) :", INFILE$: IF INFILE$="" THEN 10 Use the standard INPUT command to prompt for an entry, and print some text on the same line. The string used here is INFILE$ for the result of the input. If the result is nothing then goto line ten. 旼컴커 � 53 � 읕컴켸 5 PY = 1: OPEN INFILE$ FOR INPUT AS #1 The variable PY is a switch to indicate what part of the program we are using. If an ERROR occurs, the error routine will be able to deal with it. We OPEN the file that was entered in line 4, as an INPUT file with a file number of one. 6 INPUT #1, A$ Read in from that file to insure that it realy is there. If the file does not exist, an ERROR will occur. As soon as this happens, the routine will jump (GOTO) the routine that deals with this (starting from line 11). 7 CLOSE : PY = 0:OLDFILE$=INFILE$ If all is well and no error occurs, then we know that the file exists. So, the file is closed. The variable PY is switched OFF as we no longer need it for error checking. Now, we know that INFILE$ contains the name of the file we want to convert. As the orignal file is not to be touched, we assign it to a string called OLDFILE$. This can be printed onto the screen later as a displey. 8 LOCATE ,,1:PRINT:PRINT " Convert Document (Y/N)? :"; We switch the cursor ON by using the third parameter of the LOCATE without altering the cursor position. A blank line is printed and then some text. The semicolon on the end will place the next PRINTED text on the same line. 9 GOSUB 44:PRINT RW$:LOCATE ,,0:IF RW$="YES" THEN 14 The routine GOSUB's line 44 which has the enrty for Y or N. The responce is printed ( remember, printed after the - semicolon in line 8 ). The cursor is 旼컴커 � 54 � 읕컴켸 switched OFF. If the input from the keyboard was Y (YES for subroutine), then goto line 14 for another prompt and input by user. If this was not the case. 10 PRINT:PRINT" No action taken !! Terminate Requested.":END Print a blank line and then print some text and finish. 11 IF PY = 1 AND ERR = 53 THEN LOCATE 12, 24: PRINT INFILE$; " NOT PRESENT..TRY AGAIN..": FOR U = 1 TO 15: BEEP: NEXT: RUN Lines 11 to 13 handles ERRORS that we want to protect from. Line 11 compares the PY switch. If it is 1 then it is for the 'FILE NOT PRESENT' error. The ERR=53 denotes the error type we are looking for. So, if both conditions are TRUE, then place the cursor on line 12 at position 24. Print the File Name followed by our comment. Do a loop 15 times and BLEEP each time the loop is incremented by one. The NEXT is required to do the loop. Once completed, RUN the program again. 12 IF FLICK=1 AND ERR=>52 THEN RESUME 39 The FLICK switch is used to check for an error while converting the file. Once again, if both conditions are TRUE then the routine will RESUME to line 39. 13 LOCATE 12, 30: PRINT "DEVICE ERROR...TRY AGAIN": FOR U = 1 TO 15: BEEP: NEXT: RUN Line 13 will cover any error that we forgot to cover. It will place the cursor on line 12 and place it in position 30. Print our message, bleep 15 times and re-run the program. 旼컴커 � 55 � 읕컴켸 14 LOCATE ,,1:PRINT:PRINT" Remove Empty lines (Y/N) : ";:GOSUB 44:PRINT RW$:LOCATE ,,0 Give a prompt to the User, print responce. 15 IF RW$="YES" THEN NOSPACES=1 If the responce is Y (YES), we switch on a variable called NOSPACES to 1. In another words, this tells us that a part of the program is to used to remove blank lines form the incomming document. 16 FLICK=1 This variable is used to switch on the error checking for this part of the routine. If an error occurs, then the error handling routine (or lines) will know what to do. 17 PRINT:COLOR 23:PRINT"......Checking and converting !!!" :COLOR 7,0 Print a blank line, set the cursor to flash. Print the text and reset the cursor to normal. 18 OPEN INFILE$ FOR INPUT AS #6:ARF=LEN(INFILE$): FILE$=LEFT$(INFILE$,ARF-4)+".NEW" The documentation file is opened as file 6. A varaible ARF is set the the total length of that file name ( with its extension). We now want to change the extension to .NEW as we will not be touching the orignal file. FILE$ is set by looking at the complete name and subtracting four. The 4 is the extension plus the full-stop. 19 OPEN FILE$ FOR OUTPUT AS #7:INFILE$=FILE$ The new named file is opend to output to the disk as file 7. The orignal file name is now made into this new name. 旼컴커 � 56 � 읕컴켸 20 LINE INPUT#6,A$ Load in a LINE from the file including carrage returns and line feeds. LINE INPUT# will do this for you. It is loaded into the string A$. 21 IF VAL(A$)>=32 THEN 24 If the value of A$ is greater than or equals to 32 (space) then we jump (goto) to line 24 22 IF NOSPACES=1 AND LEN(A$)=4 THEN 20 If a request to remove spaces is active then check to see that the length is 4 (should be carrage return plus line- feed). If both conditions are TRUE then jump (goto) to 20 23 IF NOSPACES=1 AND LEN(A$)=0 THEN 20 Once again, if request for no spaces is active check for A$ being nothing. If both conditions are TRUE then 20 24 IF LEN(A$)<=78 THEN GOSUB 36:GOTO 20 If the length of A$ is below or equals to 78 then gosub the routine to save it. Now load in another line. 25 A=LEN(A$):B$=RIGHT$(A$,A-78):B=LEN(B$): A$=LEFT$(A$,A-B):IF B>78 THEN E$=RIGHT$(B$,B-78): E=LEN(E$):B$=LEFT$(B$,B-E) Set varaible A to length of A$. Make B$ (string) hold all the characters from the 79th position in A$. Set varaible B to the length of B$: Now set A$ to hold 78 characters. If the length of B is greater than 78 then we have to make a new variable and string to hold the result in. So E$ holds anything over 78 characters in B$. 旼컴커 � 57 � 읕컴켸 26 FOR I=1 TO LEN(A$):IF MID$(A$,I,1)<>" " THEN 29 We now do a loop to check the first line (A$) to see what position the first character is in. This routine will auto indent any other lines we may have. 27 ADD$=ADD$+" " This String will be placed in front of a line before it is saved. Therefor automatically indenting it. 28 NEXT This is need to complete the LOOP. 29 IF RIGHT$(A$,1)=" " OR LEFT$(B$,1)=" " AND LEFT$(E$,1)=" " THEN C$=B$:B$="":GOTO 33 Now we check each string ( A$, B$ and E$) to ensure that the word on the end of A$ is complete. That the word in front of B$ is complete and that E$ is Complete. If the conditions are TRUE, we miss the next lines. If, on the other hand, the conditions are NOT TRUE, then the next lines apply. 30 C=C+1:IF MID$(A$,79-C,1)=" " THEN C$=RIGHT$(A$, C-1)+B$:A$=LEFT$(A$,78-C):GOTO 33 The variable C is incremented by. If MID$ of A$ equals a space, then from that position we take the word and place at the front of C$ adding B$ to it. A$ now becomes shorter, as a word was removed. 31 IF C=LEN(A$) THEN 33 Here, we check that C does not become greater that the length of A$, or we would get an error. 旼컴커 � 58 � 읕컴켸 32 GOTO 30 We goto 30 to make C increment. Faster that a loop. 33 B$="":D$="" Just clear these strings. 34 IF E$<>"" THEN PRINT#7,A$:A$=ADD$+C$+E$:E$="": C=0:D=0:C$="":ADD$="":GOTO 25 First we check to see if we have a third line. If we do, then we save A$. Now make A$ have the indent plus the last two lines. It now is over 78 characters. We clear the strings and varialble we have used and goto the routine that will sort A$ out. 35 GOSUB 36:C=0:D=0:GOTO 20 If line 34's condition was not TRUE then we goto a subroutine. Once that has done its work, it returns back and we clear out varaibles C and D and then back to load in another line. 36 PRINT#7,A$ Save line one (A$) 37 IF C$<>"" THEN C$=ADD$+C$:PRINT#7,C$:C$="":A$="" :ADD$="" If line two is not empty make C$ have the indent at the begining of it'self. Save the text. Clear the variables used. 38 RETURN As this is a Subroutine, we RETURN to the calling line. 旼컴커 � 59 � 읕컴켸 39 CLOSE#6:CLOSE#7 When no more information can be loaded from the orignal named file, an error will occur. The error routine will come to this line so that we can carryon with the main program. Both files will be closed. 40 LOCATE 11,1:PRINT" New File name is :"; INFILE$". This is converted !!!" Place cursor to line 11 at position 1 and print the text followed by the new name file. 41 PRINT:PRINT" Orignal :";OLDFILE$;": Not changed !" Print a blank line and then print the text/oldfile name and the rest of the text. 42 LOCATE ,,1:PRINT:PRINT" Convert Another ASCII file ? (Y/N)";: GOSUB 44:LOCATE ,,0:IF RW$="YES" THEN RUN Switch on the cursor without altering the cursor position. Print a blank line then print some text with a semi-colon. Get responce from the keyboard. Switch off cursor. If responce was Y (YES), RUN the program again. If not......... 43 PRINT:PRINT:PRINT" Finished...Many thanks...": PRINT:PRINT" REM stands for: Realtime Employment of Memory.":END Print two blank lines, print some text. Print blank line, print some text and then END. 44 RW$=INKEY$ This is the subroutine for Y and N responces. We set RW$ to get a key. 旼컴커 � 60 � 읕컴켸 45 IF RW$="n" OR RW$="N" THEN RW$="NO":RETURN If responce is either upper/lower case N then we make RW$ say NO and RETURN to the caller line. 46 IF RW$="y" OR RW$="Y" THEN RW$="YES":RETURN If responce is either upper/lower cas Y then we make RW$ say YES and RETURN to the caller. 47 GOTO 44 Continue to get responce. End of topic. 旼컴커 � 62 � 읕컴켸 旼컴컴컴컴컴컴커 쿎ommunications� 읕컴컴컴컴컴컴켸 Alphabetical Index 216 Functional Index 220 Protect your Copyright Material 230 ANSI Colour Codes 231 ASCII Character Codes 234 Opening the Channel 64 Monitoring the Channel 70 Input from Caller 75 Check for Special Restricted Characters 78 LOCATE(ing) Screen Characters 80 Dialing out 82 Receiving/Sending Text: 85 MO-4.BAS 87 COMMAND Line Switches [Compilers] 95,212 TIME Delay [ For Action ] 97 Changing Baud Rates 99 Bulletin Board Files 101 Caller Message System 102 Make a Password Program 110 Quick Basic Compiler Vs 3.0 FIX 117 旼컴커 � 64 � 읕컴켸 Opening a Channel 컴컴컴컴컴컴컴컴� Although the word "Communications" puts fear into most peoples harts, believe me, it is not that difficult to do. I will not go into any technical jargon, all I will do, is to let you see what is happening as you go along with me. You already know how to open files to your disk/ette.It is almost as easy, using the same syntax [in general]. For those of you who use Microsoft Quick Basic Compiler 3.0, remember to link the GWCOM.OBJ code to the final .EXE file. Without this, these routines will not operate correctly in you finished program. Standard Basic Users need not worry about this problem. First we need to open a channel to the Modem. We tell it that we need to use it as a device to communicate with [ and through ] the telephone line. Which port have you plugged the Modem into ? Is it the Serial Port [ 25 pin ] at the back of the computer, or is it inside the computer [ plugged into one of the slots ] ? If outside, it is classified as COM [ Communications Port ] device 1, while inside the machine it is COM 2 or Higher. Please note..The Serial port actually has two Com Port addresses. They are COM1 and COM3. The internal fitting card will have addresses COM2, COM4 and so on. OPEN....We start to OPEN the device we want. "COM2:..The Port we need that contains that Device. If your Moden is outside the Computer, change to COM1 旼컴커 � 65 � 읕컴켸 ,1200...The Baud Rate at which your Modem will run. [ Please read your Modem Manual ]. ,N......No parity. ,8......We are using 8 bits per character. ,1......One stop bit. ,RS.....Suppress Request to Send signal. ,CS.....Wait for Clear To Send signal. ,DS.....Wait for Data Set Ready signal. We also want to tell the device that we want to INPUT from it, as well as OUTPUTing [ Reading and Writing ] with a file [device] number. The command for this is 'RANDOM AS #' and we will use the file number as 1. So, the first command will be: 10 CLS:OPEN "COM2:1200,N,8,1,RS,CS,DS" FOR RANDOM AS #1 You should use a string expression to assign what Port you are using, therefore TYPE IN ON ONE LINE 10 CLS:A$="COM2:":OPEN A$+"1200,N,8,1,RS,CS,DS" FOR RANDOM AS #1 Please see your Modem manual for the correct required speed. If you run this now, you will have an Error of the following: " Device Time out " That is to be expected, as we have not covered the program for various checks. What we now want to do, is to monitor the signal and see if: a). The Carrier has a signal. If not, continue to monitor. 旼컴커 � 66 � 읕컴켸 b). If Carrier has a signal, we need to have a reaction. c). Then, either hang up and quit or hang up and reset the Modem to re-answer. Now we need to set various parameters to look at, so that we can determine what action to take. 20 IF A$="COM1" THEN LSB=&H3F8:MSB=&H3F9:LCR=&H3FB: MCR=&H3FC:LSR=&H3FD:MSR=&H3FE ELSE LSB=&H2F8:MSB= &H2F9:LCR=&H2FB:MCR=&H2FC:LSR=&H2FD:MSR=&H2FE Notice here we use the IF THEN ELSE statements. IF COM Port 1 THEN these variables are worth this ELSE they are worth that. To read the Port we must use the INP instruction. Therefore: 30 IF (INP(MSR) AND &H40)=0 THEN 30 Here we look at the Port to check to see if the value is 0. 0 = No signal received at present. As soon as the value is changed, we have a signal and the program will continue to execute the next line. We now have to decide what to do. Let us Print on the screen the message RINGING. 40 LOCATE 12,38:COLOR 16,7,0:PRINT " RINGING ": COLOR 7,0,0 Locate the cursor on line 12 along the line at Position 38. Switch on flashing and "Inverted". Print RINGING and reset the colour to normal. 70 FOR I=1 TO 5000:NEXT We will have a delay. This is so that we can see and here whats going on. 旼컴커 � 67 � 읕컴켸 100 CLOSE#1:GOTO 10 The Modem is switched off and the the cycle is restarted. This only demonstrates the ability of the modem knowing when the telephone is ringing. What we have not done in this example is to answer the telephone and then hang up, resetting the modem to receive. We will do that now. Add these lines after line 70 71 LOCATE 12,38:PRINT"ANSWERING" 72 A$="ATQOX1V1A"+CHR$(13)+CHR$(10) A$ is set to the command to answer the telephone line. 73 PRINT#1,A$ Tell the modem to answer the line. 74 FOR I=1 TO 5000:NEXT A delay loop just for our visual pleasure. 75 LOCATE 12,38:PRINT"HANGING UP" 76 PRINT#1,"ATZ"+CHR$(13)+CHR$(10) The Modem is instructed to Hang up Receiver. 77 FOR I=1 to 5000:NEXT Another delay for our pleasure. 78 CLOSE#1:GOTO 10 The Modem is closed and we restart the routine again. 旼컴커 � 68 � 읕컴켸 Save this under the title of "MO-1.BAS" The delay loops are just to let you see what is happening, otherwise this routine will wizz along without you seeing anything. To test it out, run this routine and pick up you telephone receiver a couple of times. It depends on the type of apparatus you have. It may take a couple of "Hanging ups" to enable it to work. Alternately, you could ask someone to telephone you. If you do this, Please RUN the routine when the telephone rings. This little routine has almost done everything for you. I did say almost. What is left ? The truth is, one should always monitor all signals using a Timer. This is needed to check on the state of the Port. You need to see if it is ready to transmit or receive, otherwise problems will occur. What is also needed, is to see if a computer is on the other side of the line. If you do not do this, you would be sending a signal down the line..regardless. To do this, we either wait for a signal from the other computer and see it matches our speed, or we could send a "ARE YOU THERE" signal and wait for the response within a given time scale. The next routine will answer the line, see if there is another machine on the other side. It will hang up and reset itself. If the line has been answered, it will print the message "ITS ALIVE" and hang up. This routine now uses the TIME$ to set various time limits for watching actions taken. Various checks are made to ensure that all is well. If you are using Basic, change the loops from 9000 to around 3000. 9000 is set for Compilers. 旼컴커 � 69 � 읕컴켸 I am not going into to much detail as I belive that it is far better that you get up and running as fast as possible. Most routines can be used as they stand or be altered between each other to get the result you desire. You will have to renumber where necessary. 旼컴커 � 70 � 읕컴켸 Monitoring the channel: 컴컴컴컴컴컴컴컴컴컴컴� 1 CLS:CLEAR:CLOSE#1:DEFINT A-Z Clear the screen and any preset data. State we want to use Integer variables. 2 DEF SEG We reset to normal. 7 DEF FNTI!=CSNG(FIX((VAL(MID$(TIME$,1,2))*60*60)+ (VAL(MID$(TIME$,4,2))*60)+(VAL(MID$(TIME$,7,2))*1))) FNTI! is set using the clock. We need a single-precision figure to work on, so CSNG command is used. Also required is an Integer portion of the expression of ((VAL(MID$(TIME$,1,2))*60*60), so FIX is used. You can add PRINT FNTI! to see the result. This is necessary for us to set our sync times if the modem is to answer the line correctly. 9 IF INP(MSR)<128 THEN OUT MCR,&H4:GOSUB 6020 :OUT MCR,&H0 First check to see if the signal address is less than 128 and then it must be reset to 0 10 A$="COM2:":OPEN A$+"1200,N,8,1,RS,CS,DS" FOR RANDOM AS #1 The COM Port is 2. Change this if you are using COM1. The Baud rate here is 1200. Once again, change this if your setting is different. 20 IF A$="COM1" THEN LSB=&H3F8:MSB=&H3F9:LCR=&H3FB MCR=&H3FC:LSR=&H3FD:MSR=&H3FE ELSE LSB=&H2F8:MSB= &H2F9:LCR=&H2FB:MCR=&H2FC:LSR=&H2FD:MSR=&H2FE 旼컴커 � 71 � 읕컴켸 25 IF (INP(MSR) AND &H40)=0 THEN 25 If no signal (0) then NOT RINGING. Keep monitoring the line. 30 LOCATE 12,38:COLOR 16,7,0:PRINT " RINGING " :COLOR 7,0,0 Got a signal, so we print 'RINGING'. 35 FOR I=1 TO 9000:NEXT A delay for our benefit. 40 GOSUB 6040 Just to check and keep us in time. 45 LOCATE 12,38:PRINT"ANSWERING" Print ANSWERING for our benefit. 46 A$="ATQOX1V1A"+CHR$(13)+CHR$(10) Lift RECEIVER COMMAND 47 PRINT#1,A$ Do it ! 50 TCC!=FNTI!+30 We need another variable to set to a delay to see if anyone is out there. 60 IF INP(MSR)<128 AND FNTI!0 THEN DF$=DF$+INPUT$(LOC(1),1) ELSE 65 We check to see if our device is not in error and we get the response from the other side into string DF$. 63 IF INSTR(DF$,"CONNECT") THEN 120 If the response is CONNECT then we goto the line that will send a message. 65 IF FNTI!>=TCC! THEN 76 ELSE 60 As long as we are less than our requested sync timer we continue or we keep checking until something happens. This could be: a). The device at the other end is not responding. b). We just do not have a signal within the time. c). We are just out of sync at present. 76 LOCATE 12,38:PRINT"HANGING UP" 77 FOR I=1 TO 9000:NEXT A delay for our visual pleasure. 78 PRINT#1,"ATZ"+CHR$(13)+CHR$(10) Tell the Modem to HANG UP. 100 CLOSE 110 RUN 120 A$="Thank you for calling....Hanging up now !": PRINT#1,A$:PRINT A$:GOTO 76 A$ is setup with the message that is needed to be sent. It is printed onto the callers screen as well 旼컴커 � 73 � 읕컴켸 as our screen. Then the Modem is hung up and reset. The next section [ below ],/is where we check for timing. You can always use this routine for any type of Modem communications package that you write. 6000 DE!=FNTI!+1 We add one to the timer [sync] compare variable. This is needed to compare against the timer [ FNTI!]. 6010 GOTO 6030 6020 DE!=FNTI!+3 We add three to the timer [sync] compare variable This will be used at a later stage in the book. 6030 IF FNTI!0 THEN B$=INPUT$(1,#1) If the file is ok, set B$ to input characters. 128 R$=INKEY$ 130 IF R$<>"" THEN B$=R$ 132 IF B$="" THEN 242 If nothing has been entered we check for time. 旼컴커 � 77 � 읕컴켸 134 TCC!=FNTI!+180 Set the timer sync. 200 C$=C$+B$ The string c$ is made up by each character entered by the caller. 240 PRINT#1,C$; Print the string C$ to the callers console. 242 IF FNTI!1 THEN PRINT CURSOR_ONE$:PRINT#1, CURSOR_TWO$ 502 RETURN Providing the position of the cursor is greater than 1, THEN we print our cursor line control strings. However, if it is 1 or less, it is ignored. Now change line 138 to look like this: 138 IF B$=CHR$(8) THEN C$=LEFT$(C$,C-1):GOSUB 500: GOTO 242 Whenever you manipulate the string using MID$, RIGHT$ 旼컴커 � 81 � 읕컴켸 and LEFT$, always set your cursor position before printing to the Callers console. You can also have the response from the Caller printed onto your screen. This is done quite simply by placing another string character with the value of the Callers string and PRINT that to your screen. You can use the LOCATE command or the same control commands as used for the CALLER, or just PRINT string name. One thing must be said. Always develope your program without the worry of proper screen layout. This can be done last. Getting the program to work correctly is of prime importance. With Communications it is best to develope a system whereby you can always refer to any section on the program and KNOW what is what. 旼컴커 � 82 � 읕컴켸 Dialing out: 컴컴컴컴컴컴 All that is required is to instruct the Modem to Dial a set of digits. To activate this mode, one will use the ATDP command. AT is for Attention, D for Dial and P is for pulse. If this does not operate on your line, use the command ATDT [ T for Tone ]. So, to dial out you can either have a small routine that allows you to enter the digits or you could include them with the command string. Always set the parameters at the beginning of your program with CLS:CLEAR:CLOSE at the very beginning. This assists in preventing any problems later on. You could set all the Modem commands in the following way: M$=CHR$(13)+CHR$(10):MD$(1)="ATQOX1V1A"+M$:MD$(2)= "ATDP":MD$(3)="ATDT":MD$(4)="ATZ" and so on. M$ is set for Carriage Return plus Line Feed. MD$(1) is set for Answer line. MD$(2) is set for Dial Pulse. MD$(3) is set for Dial Tone. MD$(4) is set for Hang up. Lets say the number that you want to dial is 123456 and you want to dial using the Pulse generator. The instruction given will look like: PRINT#1,"ATDP0123456" Once the instruction is given, you still need to monitor the line. 25 IF (INP(MSR) AND &H40)=0) THEN 25 旼컴커 � 83 � 읕컴켸 What about a). If the line is engaged. b). No such number. c). Not answered. By using the subroutine in line 6000, you can give a time limit to the action that is taking place. Therefore, you would monitor the line with GOSUB 6000 instruction to check for time limit. Then continue to monitor. You do not have to do this, but its a good idea, just for safety. Once the line has been answered at the other end, you need not worry for the possible problem of "Answered But Not a Computer" as line 63 in the routine MO-2.BAS is only looking for the answering computers "CONNECT" signal. If this is not received, it automatically disconnects and reruns itself. You can also say, if the line was answered, but within a given time a "CONNECT" signal was not received, then it must be A Human. Print "HUMAN...Please Answer !" to your console, BEEP until a key has been pressed to indicate that the hand receiver has been lifted. Then reset and run or wait for a further key press to rerun. If you use this method, it is best to get the Modem to reset itself [ ATZ ] but not to rerun until you have finished the call. The reason for this is. If the program reruns before you have finished your call, it could think it is answering the line when you hang up the receiver. On most telephones, on replacing the receiver, a CLICK is produced, which could trigger off the program in thinking it has an incoming call. We have now dealt with dialing a number and checking for a human caller. But what has not been covered here, is what do we do when a computer is on the other side of the line. With the next section, I will try 旼컴커 � 84 � 읕컴켸 to show you how to respond to some aspects of getting transmitted text over the line. 旼컴커 � 85 � 읕컴켸 Receiving/Sending Text: 컴컴컴컴컴컴컴컴컴컴컴� When your program is the "CALLER", it needs to be able to receive information from the other computer. Remember, the responding Computer will always send some text to the console of the CALLING Computer. This would take the form of a). Welcome message and various information lines. b). Password and selection menus. There are a few points that must be taken into consideration. First of all, is the responding device going to wait for ASCII text to be sent to it ? And two, will it send some ASCII text and expect a response via the keyboard from the CALLING Computer ? Expect all situations ! Therefore, within any program you must be able to Receive & Send Data down the line. LINE INPUT# is quite straight forward, and is used in the normal way to receive any ASCII data. But you must also know when it is time for keyboard entry at the CALLING machines end. You could examine the incoming data for the ASCII character 1A [ -> ], but this is not always the case. Some text editors do not place 1A onto the end of a ASCII file. Or you could, once again use a TIMER variable to compare the elapse of a predetermined time to indicate TIME TO USE MY KEYBOARD. The best method is to incorporate both your keyboard and incoming data as part of one routine with WHILE EOF() command. In this way, you have control from within your program. It is important that you have keyboard input at any time, as you may want to Quit from a procedure, answer a question posed from the receiving computer and so on. Also required, is to position the cursor on your screen as the text is being displayed, as well as having the ability to display correctly as you type. 旼컴커 � 86 � 읕컴켸 Using the EOF(file number you opened the Modem with), you Input from the modem. If there is no incoming signal, then you GOTO or GOSUB to the normal keyboard input routine which will print [ using your subroutine to LOCATE the cursor on the current line ] to the other Computers console or input request routine. Remember to always monitor the telephone line, just incase the carrier goes dead. On the next page is a sample routine that should assist you to understand a little bit more. 旼컴커 � 87 � 읕컴켸 MO-4.BAS [ Will CALL and TYPE to Carrier.] 컴컴컴컴 1 CLS:CLEAR:CLOSE:DEFINT A-Z:M$=CHR$(13)+CHR$(10) Clear the screen and any preset data. State we want to use Integer variables. Set M$ to Carriage Return and line feed. 2 DEF SEG We reset to normal any preset Define Segment commands. 3 DEF FNTI!=CSNG(FIX((VAL(MID$(TIME$,1,2))*60*60)+ (VAL(MID$(TIME$,4,2))*60)+(VAL(MID$(TIME$,7,2))*1))) FNTI! is set using the clock. We need a single - precision figure to work on, so CSNG command is used. Also required is an integer portion of the expression of ((VAL(MID$(TIME$,1,2))*60*60), so FIX is used. You can add PRINT FNTI! to see what the result is. This is necessary for us to set our timer sync if the modem is to answer the line correctly. 4 IF INP(MSR)<128 THEN OUT MCR,&H4:GOSUB 6020:OUT MCR, &H0 5 CLOSE First check to see if the signal address is less than 128 and then it must be reset to 0 and close all devices. 10 A$="COM2:":OPEN A$+"1200,N,8,1,RS,CS,DS" FOR RANDOM AS #1 The COM Port is 2. Change this if you are using COM1. The Baud rate here is 1200. Once again, change this if your setting is different. 旼컴커 � 88 � 읕컴켸 20 IF A$="COM1" THEN LSB=&H3F8:MSB=&H3F9:LCR=&H3FB MCR=&H3FC:LSR=&H3FD:MSR=&H3FE ELSE LSB=&H2F8:MSB=&H2F9 LCR=&H2FB:MCR=&H2FC:LSR=&H2FD:MSR=&H2FE If we are using COM1 Port then we want to use these addresses ELSE it will be COM2 and we use those. 22 GOSUB 6040:GOSUB 6020: PRINT#1,"ATZ~M~~~AT S7=45 S0=0 V1 X1^M~" 23 GOSUB 6040 Set the timing. Initialize the Modem. This command may be different. Please see your Modem manual in SETUP section. If the Modem does not dial, then remove 22/23 and rerun again. 24 PRINT#1,"ATDP1234567890" The computer is instructed to Dial this number. Change this number for your local BBS. 25 IF (INP(MSR) AND &H40)=0 THEN 25 If no signal (0) then NOT RINGING. Keep monitoring the line. 30 LOCATE 12,38:COLOR 16,7,0:PRINT " RINGING ": COLOR 7,0,0 Got a signal, so we print 'RINGING' 35 FOR I=1 TO 9000:NEXT A delay for our benefit. 40 GOSUB 6040 Just to check the timmer sync. 旼컴커 � 89 � 읕컴켸 41 LOCATE 12,38:PRINT"ANSWERING" Print ANSWERING for our benefit. 42 A$="ATQOX1V1A"+CHR$(13)+CHR$(10) Lift RECEIVER COMMAND 43 PRINT#1,A$ Do it ! 50 TCC!=FNTI!+30 We need another variable to set a delay to see if anyone is out there. This is set for Dialing out. If you require to monitor the line for in coming calls, change to suit for your own requirements. 60 IF INP(MSR)<128 AND FNTI!0 THEN DF$=DF$+INPUT$(LOC(1),1) ELSE 65 We check to see if our device is not in Error and we get the response from the other side into string DF$. 63 IF INSTR(DF$,"CONNECT") THEN 120 If the response is CONNECT then we should send a message here or get a responce from the other Computer. 65 IF FNTI!>=TCC! THEN 76 ELSE 60 As long as we are less than our requested sync timer we continue or we keep checking 旼컴커 � 90 � 읕컴켸 until something happens. This could be: a). The device at the other end is not responding. b). We just do not have a signal within the time. c). We are just out of time at present. 76 LOCATE 12,38:PRINT"HANGING UP" 77 FOR I=1 TO 9000:NEXT A delay for our visual pleasure. 78 PRINT#1,"ATZ"+CHR$(13)+CHR$(10) Tell our Modem to HANG UP. 100 CLOSE 110 END 115 LOCATE 12,38:PRINT" ENGAGED ":GOTO 100 As the line was engaged we say so and Finish the routine. Back to DOS. 120 WHILE EOF(1) While other Computers is sendind, OK, otherwise.. 122 A$="":A$=INKEY$ Get a key from this Computers keyboard. 124 IF A$<>"" THEN print#1,a$;:goto 138 If we touched a key then it will be sent to the other Computer and your Computer screen. 126 WEND 旼컴커 � 91 � 읕컴켸 128 A$=INPUT$(1,1) Input a single character at a time from the other Computer [ Modem line ]. 130 IF A$=CHR$(13) THEN 138 If it is Carriage Return then we want to avoid printing extra lines on the screen. This is used, if you are calling a bulletin board. 135 PRINT A$; Print the character on your screen. This is for your visual support [always.] 138 GOTO 120 We continue to monitor the Input. Below is the timer routine, that supports you call. 6000 DE!=FNTI!+1 We add one to the timer [sync] compare variable. This is needed to compare against the timer [ FNTI!]. 6010 GOTO 6030 6020 DE!=FNTI!+3 We add three to the timer [sync] compare variable. This will be used at a later stage. 6030 IF FNTI!1 THEN PRINT CURSOR_ONE$:PRINT#1, CURSOR_TWO$ 502 RETURN Providing the position of the cursor is greater that 1, THEN we print our cursor line control strings. However, if it is 1 or less, it is ignored. These line would locate the characters on the line. The next line is an example for you to work on. If you build a string using A$ as the initial input and C$ as resulting string, and back DEL was pressed. 124 IF A$=CHR$(8) THEN C$=LEFT$(C$,C-1):GOSUB 500: PRINT#1,C$:GOTO 138 In this example, C$ would be one less each time the back DEL key was pressed. Have you noticed anything, yes, no protection if we reach the first character position. See what you can do for this. I would ensure that providing the cursor position is greater than 0 then allow the routine to delete the character. Does that help ? Remember that it is always a good practise to have a look at various keys and then you can prevent things getting through. What is missing here, is a line to monitor the Carrier [ telephone line ] to see if the other end has hung up on you. When this occurs, you should give a message to the screen, wait a moment, then either issue ATZ and a CLOSE command or just CLOSE and rerun the routine. If you decide to have other routines within the program, you could go and do those. 旼컴커 � 94 � 읕컴켸 The next thing you can use a GOSUB in line 135 to assist to in the location of the printed characters on the screen, as well as assisting with the layout when printing over the Modem. Once again, it depends on if you are going to send a message first [ As with a program that acts like an Answer Machine ], or as a Caller program, which monitors for characters from the other side as well as allowing keystrokes being entered from this side of the program. It is a choice that you have to make on the outset of your design. The next two routines that are included in this book are for demonstration proposes. A bit of fun, just to let you have a breather. 旼컴커 � 95 � 읕컴켸 COMMAND LINE SWITCHING 컴컴컴컴컴컴컴컴컴컴컴 Another demo program is given on page 212. Save this as SWITCH-1.BAS There is a small routine for those of you who like to use COMPILERS. This routine was the one I added into S.A.M Sysop's Answer Machine for Master Gossage, Which I did a complete revised version on his behalf. This routine just delivers some messages according to the switch you entered. 0 IF$=COMMAND$:A=LEN(IF$):IF IF$="" THEN 570 The command line in DOS is examined for any extra characters. 'A' is set for the length. If no extra characters were found, then the program goes to a display screen. 204 in this case just has a REM statement and then 205 which ENDs the program. 4 FOR I=1 TO A 5 C=ASC(MID$(IF$,I,1)) 6 REM**SORT INTO UPPERCASE 24 IF C=44 OR C=46 OR C=47 OR C=32 THEN 64 44 C=ASC(MID$(IF$,I,1)) AND &HDF 64 F$=F$+CHR$(C) 65 NEXT 66 IF$=F$ 84 IF IF$<>"/R AND IF$<>"/E" THEN 144 104 IF IF$="/R" THEN 564 旼컴커 � 96 � 읕컴켸 124 IF IF$="/E" THEN 564 144 PRINT:PRINT"WRONG SYNTAX ! USE THE FOLLOWING:" 145 PRINT:PRINT"SWITCH-1 TO RUN NORMALLY." 148 PRINT"SWITCH /E GOTO EDIT SETUP." 149 PRINT"SWITCH /R TO RUN." 150 END 564 CLS:IF IF$="/E" THEN PRINT" YOU SELECTED /E":END 568 IF IF$="/R" THEN PRINT"YOU SELECTED /R":END 570 PRINT"PROGRAM TO RUN NORMALLY":END You can alter the lines to suit your program. To get this routine to operate correctly, Compile it as DOS-1.EXE and then run it with one of the switches. As an example: DOS-1 /R DOS-1 /E DOS-1 / DOS-1 Each switch will give you a responding message. I always recommend that where possible, the use of Switches should be made available for the more advanced User. 旼컴커 � 97 � 읕컴켸 TIME DELAY FOR ACTION 컴컴컴컴컴컴컴컴컴컴� This could be used as part of the Command line switching. If you selected /R then goto the start of this routine. Alternately, you could use this as a fail safe method, just incase a part of a routine was selected incorrectly. This Routine [ is once again, an addition I placed in S.A.M ]. The delay is for 10 seconds for the routine to run, but there is also a keyboard entry system during that time which will allow for actions to take part before that time elapses [Not included.] Save this as DELAY.BAS 7165 DDD$=TIME$ 7166 TIME$="00:00:00" 7167 LOCATE 8,23 7168 PRINT"A DEMONSTRATION OF A TIME DELAY AND SELECTION" 7169 LOCATE 10,13 7170 PRINT"(E)....GOTO EDITOR (Q)...QUIT (R)... RUN" 7184 G$=INKEY$ 7185 IF G$="Q" OR G$="q" THEN TIME$=DDD$:END 7204 IF G$="E" OR G$="e" THEN TIME$=DDD$: PRINT"YOU SELECTED EDITOR":END 7224 LOCATE 12,23 7225 PRINT"AUTORUN IN 10 SECONDS....";RIGHT$(TIME$,2) 旼컴커 � 98 � 읕컴켸 7226 FFF$=RIGHT$(TIME$,2) 7227 IF FFF$="10" THEN TIME$=DDD$+FFF$:PRINT"TIME DONE": END 7244 IF G$="R" OR G$="r" THEN TIME$=DDD$:PRINT"RUN": END 7264 GOTO 7184 I've reset the TIMER to 00 in this example and assigned the original time to DDD$. However, this is not a great way to do things. I suggest that you use a Variable to setup the control. Using switches gives your programs a professional touch while allowing the User various methods of operating your programs. 旼컴커 � 99 � 읕컴켸 Changing Baud Rates 컴컴컴컴컴컴컴컴컴� [300 to 2400] It is always nice to change the baud rate from within the current program. There is quite a lot of factors to be taken into consideration. Firstly, if the change is to be done from within the program, are you looking at a configuration file from disk. This would be to verify the callers Name, Password and baud rate. Secondly, if you require to change the baud rate directly from the program and from looking at the signal that was received, then it becomes more complicated. BE VERY CAREFUL AND TYPE IN EXACTLY WHAT IS LISTED BELOW. THE 'OUT' COMMAND [ IF USED INCORRECTLY ] CAN CAUSE PROGRAM CRASHES, OR EVEN DAMAGE. In line 63 of the program MO-4.BAS, the line would look like this. 63 IF INSTR(DF$,"CONNECT") THEN RATE=VAL(MID$(DF$ ,INSTR(DF$,"CONNECT")+8,4)):GOTO 600 Add the following starting with line 600 600 GOSUB 800 605 IF RATE=0 OR RATE=300 THEN RATED=&H180:PERSEC=-1: GOSUB 700 ELSE IF RATE=1200 OR RATE=2400 THEN PERSEC= -2-(RATE/1200):RATED=48*(PERSEC+5):GOSUB 700 ELSE 61 610 GOTO 120 Now add: 699 REM TO CHANGE TO CALLERS BAUD RATE 700 A1=INP(LCR):A2=INP(MSB):OUT MSB,0 旼컴컴� � 100 � 읕컴컴� 705 OUT LCR,A1 OR 128 710 IF RATED=384 THEN OUT LSB,&H80:OUT MSB,&H1:GOTO 730 715 IF RATED=256 THEN OUT LSB,&H0:OUT MSB,&H1:GOTO 730 720 IF RATED=96 THEN OUT LSB,&H60:OUT MSB,&H0:GOTO 730 725 IF RATED=48 THEN OUT LSB,&H30:OUT MSB,&H0 730 OUT LCR,A1:OUT MSB,A2:RETURN 799 REM CHECK RESPONSE TIME IN 3 MINUTES 800 WHILE NOT EOF(1) 805 DF$=INPUT$(LOC(1),3) 810 WEND 815 RETURN If your Modem has a single baud rate, it would still be advisable to add this routine to your program. After all, if you write programs for other people, they may have the facility in their Modems to have various Baud rates. It is important to state, that it takes a little practice to actually get the rate to change. Try to printout [ on the screen ] the RATE and the RATED variables and see what is the actual values are. This part is only a guide line for future references. As I said, you have to know exactly what addresses are to be looked at and how to alter them. This is not within the scope of this book. 旼컴컴� � 101 � 읕컴컴� Bulletin Board Files 컴컴컴컴컴컴컴컴컴컴 If your modem has the facility to change its Baud rate, then you could ask the Caller for His or Her Name with a Password. Then look at a special table file which has all the information of the users. As they enter their name and password, you could check to validity. If either Name or Password was incorrect then you could open a file, using the APPEND command, and save the details of all users that failed to complete their entries. You could make things very difficult for unauthorized entry, by allowing the Names and Passwords [ or sentence ] to be in mixed cases. This would allow ALPHA and Numeric and even special characters. The combinations of failure increase with every extra possible entry. I like using multiple entry systems with long lines. for example, as a password: PRogRaMmer ExTROdiNAiRE Imagine the problem of trying to crack this beauty. Thats not all, add Numbers, special characters and you have a pretty good bit of protection. What could be added, is, while the Caller is typing, a check for each character could be done. This now adds to the complexity of the Caller trying to crack the access code. There again, If someone is using a routine to crack the codes, then don't check each letter except for unwanted control characters. With BBS systems, often people with security clearance to access the DOS and rummage around someones computer, have quite an easy entry. However, with a little routine with these options [ with the checking of those control codes etc; ] you have the almost crack free system. There is nothing in this world that is 100% perfect, only degrees of near perfection. 旼컴컴� � 102 � 읕컴컴� Caller Message System 컴컴컴컴컴컴컴컴컴컴� This routine is to be added to MO-2.BAS and then saved as MO-5.BAS. The line numbers may have to be changed to suit you application program. What this does is allow the Caller to place a message, Edit, List, Continue and Abort. This routine would start in line 120. You could place a gosub 7000 instead of what it has. If you want to see what is going on then place a PRINT with the string or variable expression after each PRINT# statement. You can just remove the #1, from the PRINT statement to display onto the screen. Remember to replace them when you want to use the routine correctly. Change the input routine to match an input from your keyboard. First add these three parameters to the beginning of the program. DIM LI$(90) CURSOR_ONE$=CHR$(8)+CHR$(32)+CHR$(8) CURSOR_TWO$=CHR$(29)+CHR$(32)+CHR$(29) Now you can enter the following: 7000 PRINT#1,"E)dit, L)ist, C)ontinue, A)bort."+M$; Print to the Modem the selection. 7010 GOSUB 7100 Get a response from the callers keyboard. 旼컴컴� � 103 � 읕컴컴� 7020 C$=LEFT$(B$,1):IF C$="E" OR C$="e" THEN 8010 Set C$ to the first character. If the Caller wants to EDIT then we goto that routine. 7025 IF C$="L" OR C$="l" THEN 8100 If the Caller wants to LIST then we goto that routine. 7030 IF C$="C" OR C$="c" THEN 8200 If the Caller wants to CONTINUE with His or Her message then we goto that routine. 7030 IF C$="A" OR C$="a" THEN 76 If the Caller wants to ABORT, then we HANG UP. 7050 A$="SYNTAX ERROR....Try again !"+M$ If none of the above keys was selected the there was a keyboard entry error. A$ is assigned the text. 7055 GOSUB 6040:PRINT#1,A$ We gosub to the time delay routine and the print the error message that we set in A$. 7060 GOTO 7000 The we restart the display. Line 7100 monitors the input response via the Modem line. 7100 B$="":TCC!=FNTI!+180:LOCATE,,1 B$ is cleared out. The time factor is increased, and the cursor is switched on. 旼컴컴� � 104 � 읕컴컴� 7105 IF EOF(1) THEN 7125 We check to see if we have an input character. 7110 A$=INPUT$(LOC(1),3) We set the input file#1 to a time limit of 3 minutes. 7115 GOSUB 6000 Jumps to the subroutine timer. 7120 GOTO 7105 Back we go again to get input. 7125 A$="":IF (INP(MSR) AND &H80)=0 THEN 76 Watch out for the Carrier to be dropped on us. If it is, we also hang up. 7130 IF EOF(1) THEN 7140 Has anything been entered. 7135 IF LOC(1)<>0 THEN A$=INPUT$(1,#1) 7140 Y$=INKEY$ 7145 IF Y$<>"" THEN A$=Y$ 7150 IF A$="" THEN 7200 7155 TCC!=FNTI!+180 Increase the timer. 7160 IF A$=CHR$(8) AND LEN(B$)=0 THEN 7200 If the back DELete was used and no characters were assigned to B$, then we jump to check time delay. 旼컴컴� � 105 � 읕컴컴� 7163 B=LEN(B$):IF A$=CHR$(8) THEN B$=LEFT$(B$,B-1): GOSUB 8000:GOTO 7200 If the back DELete key was used then B$ is subtracted one character from the right. 7165 IF A$=CHR$(10) THEN 7200 7170 IF A$=CHR$(13) THEN 7210 The Caller has finished entering a line. 7175 IF (ASC(A$)>96) AND (ASC(A$)<123 THEN A$=CHR$( ASC(A$)-32) Set a limit on characters that are used. 7180 IF LEN(B$)>78 THEN PRINT#1,CHR$(7);:GOTO 7200 The line length is limited to no more than 78. 7185 B$=B$+A$ 7190 IF UC=-1 THEN A$="." 7195 PRINT#1,A$; 7200 IF FNTI!1 THEN PRINT CURSOR_ONE$;:PRINT#1, CURSOR_TWO$; 8005 RETURN Now for the Editing facility. 8010 PRINT#1,M$+"Enter line number to Edit or Q to Quit : "+M$; Print to the Callers console the above message. 8020 GOSUB 7100 Monitor the entry. 8025 CHECK$=LEFT$(B$,1): IF CHECK$="q" OR CHECK$="Q" THEN 7000 If the Caller selected Q for Quit, we then goto the beginning of the display prompt. 8030 B=VAL(B$) Set B variable to the value of B$. 旼컴컴� � 107 � 읕컴컴� 8035 A$=STR$(B)+" >"+LI$(B) We assign A$ for the displaying of the line number with the text. 8040 GOSUB 6040:PRINT#1,A$ First do the time delay then print the line etc; 8045 PRINT#1,B;">"; Print the line number to be edited without the text. 8050 GOSUB 7100 Monitor the Callers keyboard response. 8055 LI$(B)=B$ Assign the current string to the dimensioned string. 8060 GOTO 8010 Back to the ENTER LINE NUMBER OR ... message. 8100 COUNTER=1 Set the counter variable to 1. 8105 IF LI$(COUNTER)="*** END ***" THEN 8135 If the current dimensioned dimensioned string is END then jump to line 8135 8110 FM$=STR$(L) 8115 A$=FM$+":"+LI$(COUNTER) 8120 GOSUB 6040:PRINT#1,A$+M$; 8125 COUNTER=COUNTER+1 旼컴컴� � 108 � 읕컴컴� Increment the counter by one. 8130 GOTO 8105 8135 A$=M$ 8140 GOSUB 6040:PRINT#1,A$+M$; 8145 GOTO 7000 Below is the routine to Continue. 8200 A$="Press ENTER on blank line to end entry !"+M$ 8205 GOSUB 6040:PRINT#1,A$+M$; 8210 COUNTER=1 We set a variable as COUNTER to use. 8215 IF COUNTER=20 THEN LI$(COUNTER)="*** END ***": GOTO 7000 If the counter has reached 20 then it is the end of the possible entry for the Caller. The routine will restart the display. You could place a subroutine to save the text using the APPEND command. 8220 PRINT#1,COUNTER;">"; Line number is printed ready for the text entry. 8225 GOSUB 7100 Scan for key entry. 8230 IF B$="" THEN LI$(COUNTER)="*** END ***: GOTO 7100 If nothing has been entered the the last [ or current string is assigned. 旼컴컴� � 109 � 읕컴컴� 8235 LI$(COUNTER)=B$ The entry of B$ is assigned to the current string. 8240 COUNTER=COUNTER+1:GOTO 8215 The counter is incremented by one and then the routine continues to monitor both the line count and the key entry. I have omitted a few PRINT# statements for you to add. By making this routine work on the screen, you will see when the text is not printed onto the screen. PLEASE SAVE THIS as MO-5.BAS. With additions, you could have a very nice routine to get the Caller to operate. You must always remember to cover your program with REM statements, so that you can come back to it at any time and know exactly What does What and where the branches are. There really is no point writing very long Code when the thread of it can be lost. 旼컴컴� � 110 � 읕컴컴� Make a Password Program 컴컴컴컴컴컴컴컴컴컴컴� The following routine contains all the necessary information to build a realy good entry system. It has been written [ although in a fairly long form ], to look up a Password and Entry file and compare it with the incomming information. It will then Shell to DOS [ as one would if the Caller has the security clearence ] and APPEND the information of the Caller to a file, with His or Her full details. You will have to covert the routine to work on the Modem, as this demonstration only uses your screen and keyboard. You must first make up the three files that this program will use in one form or another. Use you ASCII text editor or the COPY CON method. The first will be called OK.DAT and look like this: ....NAME Passwords 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� Peter Wallis*This is a test The next will be called BAD.DAT and look like this: ....Name Town Sec Call *Logged System* Tel N0. Baud 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 NOTE ! Sec is the Security level of the Caller. 컴컴컴 The third will be called INFO.DAT and look like this: Note..[ The 'REM statements MUST be removed. ] Peter Wallis 'REM Full name of caller 0 Leaf Town 'REM town 1000 'REM Security level 旼컴컴� � 111 � 읕컴컴� 000 A Let Me In 'REM Standard Password 0 0 08:23 19:29 05/05/90 A 0 999 0 0 0000000000 02/05/90 19:29 A A 02/01/90 0 0 0 0 0 0 A COM2 'REM change this if COM1 07/24/52 1200 'REM Baud Rate of Callers Modem A A 02/06/90 00:29 0 0 REMOVE all REMs and save it now please. This last file is similar to a file created by the WILDCAT BBS Sysops Program. If you are using this type of program, then this just might be the thing you are looking for. 旼컴컴� � 112 � 읕컴컴� Here is the main program for you. Remember to keep typing and then press ENTER. Each line will be a continious line of commands. 1 CLEAR:COLOR 7,0,0:CLS:DIM A$(27),BB$(36): ON ERROR GOTO 251:OPEN "i",9,"BAD.DAT":INPUT#9,JK: OPEN "i",10,"OK.dat":INPUT#10,A$: OPEN "i",11,"INFO.DAT":INPUT#11,DGF$: OPEN "I",12,"INFO.DAT":FOR TE=1 TO 33: INPUT#12,BB$(TE):NEXT 11 CLOSE#9:CLOSE#10:CLOSE#11:CLOSE#12: IF SWITCH=1 THEN 311 21 TIMER ON:PRINT"旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 컴커":PRINT"쿎.P.White (C) 1989 (FOR MODEM BOOK) �" 31 PRINT"�";:COLOR 0,7:PRINT "DROP TO DOS REQUEST";: COLOR 23,0,0:PRINT" 2 Minutes only!";:COLOR 7,0:PRINT "�":COLOR 7,0:PRINT "읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 컨컴켸" 41 PRINT:PRINT "* * * Quit = ENTER three times. * * *": PRINT 51 PRINT"Penalties may be encountered if you":PRINT: PRINT"are not a registered SYSOP user!!":PRINT: ON TIMER (120) GOSUB 271 61 IF SWITCH=2 THEN 291 71 RS$(1)="Name or Names :":RS$(2)="Your password :": RS$(3)=RS$(2):FOR KL=1 TO 3:IF KL>1 THEN PRINT CHR$(10); 81 PRINT RS$(KL);:LINE INPUT;A$(KL):NEXT: IF A$(1)="" AND A$(2)="" AND A$(3)="" THEN PRINT: PRINT:PRINT" Returning without penalties ": KK$=" Aborted ?":GOTO 291 旼컴컴� � 113 � 읕컴컴� 91 OPEN "i",11,"OK.DAT":INPUT#11,XC$:INPUT#11,XXC$ 101 WHILE NOT EOF(11) 111 POI=POI+1:INPUT#11,DSA$:FOR UYT=1 TO LEN(DSA$): AZZ$=MID$(DSA$,UYT,1):IF AZZ$="*" THEN 161 121 AZS$=AZS$+AZZ$ 131 NEXT:IF AZS$=A$(3) THEN 181 141 DSA$="":GOTO 101 145 WEND 151 CLOSE#11:GOTO 181 161 IF A$(1)=BB$(1) AND A$(1)=AZS$ THEN AZS$="": GOTO 131 171 AZS$="":GOTO 131 181 SRT=VAL(BB$(4)):IF BB$(1)<>A$(1) AND SRT<1000 THEN KK$=" security risk":GOTO 281 191 IF BB$(1)=A$(1) AND SRT<1000 THEN KK$=" no clearence":GOTO 281 201 IF BB$(1)<>A$(1) THEN KK$=" bad name": GOTO 281 211 IF BB$(7)<>A$(2) THEN KK$=" bad BBS pass": GOTO 281 221 IF AZS$=A$(3) THEN KK$=" ok �":GOTO 291 231 IF AZS$<>A$(3) THEN KK$=" bad DOS pass":GOTO 281 241 KK$=" ????????? ":GOTO 291 旼컴컴� � 114 � 읕컴컴� 251 IF ERR=53 OR ERR=64 OR ERR=52 OR ERR=53 THEN PRINT:PRINT:PRINT"SORRY...Sysop withdrawn this facility for now.": FOR I=1 TO 1000:NEXT 261 IF SWITCH<2 THEN SWITCH=1:RESUME 11 271 PRINT:PRINT" **** OUT OF TIME ****":SWITCH=2:KK$=" time out":RETURN 61 281 PRINT:PRINT" You have either entered incorrect ly or CLEARENCE has NOT been given !" 291 CLOSE#11:BJ$=BB$(1)+" "+BB$(3)+" "+BB$(4)+" "+ BB$(10)+" "+BB$(11)+" "+BB$(17)+" "+BB$(31):BJ$=BJ$+ KK$:OPEN "BAD.DAT" FOR APPEND AS #9:PRINT#9,BJ$: CLOSE#9:IF KK$=" ok �" THEN 301 ELSE GOTO 311 301 TIMER OFF:COLOR 7,0:PRINT:PRINT "Type EXIT when ready to return to CALER Program !":SHELL 311 TIMER OFF Now save this routine as PASSWORD.BAS When changing this program to work on the Modem, remember to change the LINE INPUT to check for the Delete key. Also to create a string that holds the created text, this will be reduced by one when the Delete key is used. You must LOCATE the cursor and use the POS command. Running this routine will produce three entries. The first will be the actual Name [ in the correct format ] that you log onto a BBS system. The second, will be the password for using the BBS board. You can remove this, if you do not require. The third is the special password to SHELL to DOS. All these must be typed in exactly, Uppercase and Lowercase letters. Where the special password is conserned, it may have any combination of any characters and so on. 旼컴컴� � 115 � 읕컴컴� There is a two minute countdown for the entries to be completed. As this routine only uses the straight foreward INPUT routine, you will have to alter it slightly to monitor the TIMER between each character entry. You can add some extra conditions to stop unwanted characters getting through. First make sure that you have Saved the routine then RUN it. Type in Peter Wallis and press Enter, then type Let Me In. So far all is well. Now just type in anything. The file BAD.DAT will be APPENDED to, as the last password was not correct. Re run the routine and type in everything correctly, with the third line as "This is a test". The routine will now SHELL to DOS. You can use TYPE BAD.DAT to see the file of callers. Once finished, type EXIT and press ENTER. In this demo, the routine will return to itself and then just exit. You could use a preset Batch file [ if you Compile the routine with QB 3.0 etc; ] to control the action of this program. This could have the name of this program first, then the name of the calling [ or main program ] that allowed this routine to operate. This routine will also check the security level of the caller. If it is less than 1000, even if all the information entered was correct, the Callers details will be APPENDED to the BAD.DAT file. This was done, just incase the Caller was demoted for one reason or another. A small bonus, is that if any of the configeration files were removed, the Caller will not be given access to the routine and returned to the Parent program. Once again this was done for a good reason. If the Sysop decided to withdraw this facility, for any reason then He or She just has to rename one of the files. 旼컴컴� � 116 � 읕컴컴� I decided to add this routine as a normal procedure to get you thinking on how to get it to operate correctly over the Modem. The methods are available within the other routines. Have a go at it. You'll be suprised what you have learned so far. 旼컴컴� � 117 � 읕컴컴� Quick Basic Compiler Version 3.0 FIX 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 If you are using Quick Basic Compiler Vs 3.0, you may like to know that there is a problem with the Carrier being dropped when exiting from a Compiled program. To eliminate this, the following Patch can be used. 旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� � NEVER EVER ALTER THE ORIGNAL PROGRAMS !!!!� 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� Copy both BCOM30.OBJ and BRUN30.EXE to a seperate diskette with DEBUG. Rename BRUN30.EXE to BR.X Now type in the following from the DOS prompt: DEBUG BCOM30.OBJ -a DC0B xxxx:DC0B Mov AL,1 xxxx:DC0D W Q Now type in the following: DEBUG BR.X -a 6969 xxxx:6969 Mov AL,1 xxxx:696B W Q Rename BR.X to BRUN30.EXE and you are ready to use these when compiling. A different Fix to the problem is with the GWCOM.OBJ file. Use a Disk Editor and Replace the word COMCLOSE with spaces. When you produce your EXE file, LINK yourFile GWCOM,,; do not worry about all the error mesages thrown up. Your program will work perfectly it all aspects. 旼컴컴� � 118 � 읕컴컴� REFERENCE: BASIC and its commands. The direct command from DOS: BASIC[prog][][][/c:buffer] [/d][/f:files][/m:[address][,blocks]] [/s:buffer][I] prog Execute a program after interpreter has loaded.If not stated then a READY prompt will be displayed. out File or device to direct output to. /c:buffer Size of data buffer when communications adaptor used. Default 256 with maximum of 32767 bytes. /d Mathematical function. ATN, EXP, LOG, SIN, SQR and TAN. All using double-precision mathematics. /f:files Total amount of files accessed at one time. Default 3 with maximum of 15. /m:address,blocks Normally 64k. Can protect a portion of memory at highest level above Interpreter. /s:buffer Random Access file default length is 128, maximum 32767. 旼컴컴� � 119 � 읕컴컴� /I Allocates a Dynamic space to support file operations. 旼컴컴� � 120 � 읕컴컴� The BASIC Editor and its commands 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� AUTO [stln/.][,inc] stln Start first line number. Default is 0. . Current line. inc Incrementation between lines required. CLEAR [data][,stack] data Reserve area for variables. Machine Code can be entered by decreasing the default [65535]. stack Reserve memory on the stack. Default 512 bytes. CLEAR on its own will clear all variables from memory. CONTD Continues a program that has been stopped by usingthe CTRL/BREAK key or by an END or STOP command within a program. If a program has halted due to a fault in the program, then it can not be restarted. DELETE [stln/.][-[endln/.] stln Start line to delete. . Current line number. - Deletes both start and end lines stated and all between. If not stated then lines from the start to the end will be deleted. If 'endln' is not stated after the minus then all lines from the beginning of the program to the stln will be deleted. 旼컴컴� � 121 � 읕컴컴� endln End line to delete to. EDIT [ln/.] ln Line number currently changed. . Abbreviation for current line. FILES ["flspc"] flspc Files on directory. Example: ".DOC" displays all files with the extension of .DOC If FILES is used on its own then all files will be displayed on current directory. FRE(0) or FRE("") FRE(0) Displays free memory. FRE("") Does the same thing by removing unused string space variables. This does a garbage collection. GOTO ln ln States which line number to execute a program from. KEY ON/OFF/LIST ON 25th line displays current settings. OFF Switches function keys off. 旼컴컴� � 122 � 읕컴컴� LIST Displays to screen the current settings. KEY num,strn num From 1 to 10 to assign function keys to specific tasks. strn Maximum programmable characters is 15 per function key, each can contain control characters. If "" (double quotes) are expressed then the num is disabled. LIST [from/.][-[to/.]][,dev/filspc] from First line number. . Abbreviation for current line number. - Separation between from and to line. to Last line number. dev Program to be listed to a curtain device. filspc File to be listed. LLIST [from/.][-[.to] from Program to be listed from first line to a printer. . Abbreviation for current line number. 旼컴컴� � 123 � 읕컴컴� - Separation between from and to line. to Last line required to be listed to a printer. LOAD "[drv:\path\file"][,R] drv: Drive from where the program is to be loaded. \path Name of directory. \file A Basic program to be loaded. ,R Run the program after it has been loaded. If programs are on the current drive, then drv, /path ,R can be omitted. ,R is optional. MERGE "[drv:\path\file.BAS]" drv Merge a program from a drive. \path Name of directory. \file Program to be merged. .BAS Can be omitted as BAS extension is assumed. If programs are on the current drive, the drv and \path can be omitted. The file must be in ASCII format [saved with the ,A command (see SAVE)] and must have higher line numbers than the current file in memory. If the file being merged has a start line number lower or equal to the one in memory then it replaces those lines. 旼컴컴� � 124 � 읕컴컴� NEW Removes a program from memory, initialises all variables. REM or :REM txt/'txt txt Can be any character. Used as remark statements which are not executed by the Basic Interpreter, but does take up memory with the exception of Quick Basic Compiler which when compiled does not include these statements as part of the finished .EXE file. ' Quick Basic Compiler will use this (if required) on its own instead of the REM statement. RENUM [newln/.][,fromln/.][,inc] newln Start renumbering to this new line number. fromln Starts renumbering from this current program line number. inc Set incrementation (step) between line numbers. Can be omitted. Default is step 1. . Abbreviation for current line number. RUN ["[drv:\path\][stln/."]] [,R] drv: Drive from where program is to loaded. 旼컴컴� � 125 � 읕컴컴� \path Directory name. \stln The start of a line from which the program will be executed. . The current line within memory. ,R This indicates all open files are to remain open. RUN or RUN stln/. Are used to run a program from within memory. All other commands are used for loading programs and running them with various parameters. stln Start of line number to execute program. SAVE "drv:\path\nme"[,A/,P] drv: Drive on which program is to be saved. Can be omitted. \path Directory name. Can be omitted. \nme Name of program to be saved. The extension can be named. If a file name saved is the same as a file on the disk/ette then it will be overwritten. ,A Save a file in ASCII format. 旼컴컴� � 126 � 읕컴컴� ,P Save a file to disk in protected format, which can not be listed or edited. STOP This command will stop a program at a certain point while it is running. 200 FOR I = 1 TO 100 : NEXT : STOP 210 BEEP When the loop has finished the program will stop with a statement of: Break in line 200 You can continue the program from the next line by using CONT command providing a error has not occurred. SYSTEM This will return you to DOS, leaving the Basic Interpreter completely and not saving the current program in memory. TRON/TROFF A trace facility which can be turned ON and OFF which displays the current line being executed. 旼컴컴� � 127 � 읕컴컴� Similar DOS type commands in Basic: CHDIR, MKDIR and RMDIR CHDIR path Change path MKDIR dirname Make a new sub-directory RMDIR dirname Remove sub-directory Abbreviations can not be used as in DOS. ENVIRON entry = assignment DOS stores information about the environment. This can be accessed from Basic. entry PATHs, COMSPEC or parameter specified by SET. assignment A new parameter to be set to entry. ie; ENVIRON "PATH = B:\PETER" or ENVIRON "PROMPT = $p$_$n:" ENVIRON$ ("entry") or (num) The information stored in DOS about the environment can be accessed. entry A legal variable like PROMPT, PATH etc. The return assignment is displayed. PRINT ENVIRON$ ("PATH") The readout may be... B:\MASM 旼컴컴� � 128 � 읕컴컴� IOCTL # filenum, control_string A control string is sent to a device driver which has already been OPENed. The MS-DOS drivers will not except IOCTL strings. filenum File number used when file OPENed Control_string The number containing data to be evaluated by the driver IOCTL$ ie, A$ = IOCTL$(# filenum) The answer from the device driver given to a control string sent by IOCTL$. filenum File number used when OPENed. SHELL filespec (optional. Files or DOS) Filespec A program to be executed which must be enclosed with "". Used at DOS level. ie, SHELL"DIR" COMMAND.COM must be present on the disk. if the 'filespec' is found, then on returning to the program, the next line will be run. TIMER ie, A = Timer The 'A; will return the time elapsed from midnight (0:00 hours) in seconds/hundreds. Independant of set time. Some versions will give aresult from the time the computer was turned on. 旼컴컴� � 129 � 읕컴컴� Shortcut KEYS for the Editor 컴컴컴컴컴컴컴컴컴컴컴컴컴컴 These may differ depending on the version of Basic. Using the ALT key with another: A = AUTO B = BSAVE C = COLOR D = DELETE F = FOR G = GOTO H = HEX$ I = INPUT J = unused K = KEY L = LOCATE M = MERGE 旼컴컴� � 130 � 읕컴컴� Editing keys 컴컴컴컴컴컴 Enters the current line in memory ENTER or CTRL/M All Input/Output is redirected to the printer. CTRL/P or CTRL/PrtSc Clear screen and place cursor top left. CTRL/Home or CTRL/L Clear rest of program line from cursor. CTRL/End or CTRL/E Clear line, place cursor at start of line. ESC Clear rest of screen from cursor line. CTRL/Z or CTRL/PgDn Delete character under cursor. Del Delete character left of cursor. Backspace or CTRL/H Delete program line to next colon or space. PgDn Insert blank line within the program line. CTRL/ENTER or CTRL/J Move the cursor right to the next tab position. Tab or CTRL/I Put cursor at end of line. End or CTRL/N Put cursor top left of screen only. Home or CTRL/K 旼컴컴� � 131 � 읕컴컴� Move cursor to start of next word. CTRL/-> Move left to start of previous word. CTRL/<- or CTRL/B Stop screen listing. Press again to undo. CTRL/+ or Num Lock End edit mode and cause any changes to be lost. When running a program, the control keys will return Basic into the direct mode: Command is CTRL/C or CTRL/Break. Print the current screen contents to printer. If using graphics mode, use the GRAPHICS.COM file supplied with some PC's. Command is Shift/PrtSc. Scroll the listing up. Cursor must be on a line number to operate correctly. Command is CTRL/Y or CTRL/cursor down. Scroll the listing down. Cursor as above. CTRL/X or CTRL/cursor up. Toggle between overwrite and insert. Ins or CTRL/R Show function key operations on 25 line. CTRL/T 旼컴컴� � 132 � 읕컴컴� File Handling 컴컴컴컴컴컴� CHAIN [merge] file[stln][,all][,delete fromln-toln] Programs requiring CHAIN must be saved in ASCII format with the ,A. merge Used in earlier versions of Basic and still maintained depending on the version of Basic you have. Same effect as the CHAIN command. The program is executed at the stln (start line) given. file ie; drive:\path\ stln Starting line which will execute when CHAINed. all Preserves all existing variables. If not used, then the variables will be erased from memory. See COMMON for specified variable protection. delete fromln-toln Deletes line numbers as stated: fromln From first line number. - Separator. toln To last line number. CLOSE [# filenum,...] The CLOSE command on its own will close all open files. 旼컴컴� � 133 � 읕컴컴� # filnum File number which has been opened. When closed, an error message will occur if attempts are made to read or save to it unless it has been re-opened. COMMON var,... var The variable/s and or arrays [separated with comers] to be preserved whilst using CHAIN command. A DIM command must follow a COMMON command and the variable/s and or arrays must be assigned a value. CVD, CVI & CVS Converts data compressed with MKD$, MKI$ and or MKS$ to numeric value. CVD Returns a double-precision result. CVI Integer result. CVS single-precision. ie: A = CVD [ fieldvar ] fieldvar .. A named field variable which was assigned a string by MKD$, MKI$ and or MKS$. EOF# [filenum] filenum Number of file when opened. Test if end of file reached when reading a file. 旼컴컴� � 134 � 읕컴컴� FIELD# filenum,length AS stringvar,... filenum The file number used when opened. length AS stringvar The length of individual fields of a buffer. This is for buffer variable/s used to read/write to random access files. LSET and RSET must be used before they are written to a file using the PUT# command. GET# filenum[,recnum] filenum The file number used when a file is opened. recnum Number to read of an open record. Values from 1 to 16,777,215. INPUT# filenum,var,... filenum File number used. var Variable/s stored in a data file. Arrays can be used. INPUT$ IE, INPUT$[numchars[,#filenum]] numchars Number of string characters read from a file. Value 1 to 255. filenum Number used when file opened. 旼컴컴� � 135 � 읕컴컴� KILL "drv:\path\filespec" "drv: Drive required. Optional. \path Sub-Directory required. Optional. \filespec" Deletes a file name. LINE INPUT# filenum,stringvar line input# Read characters from a file until 255 characters have been loaded or until carriage return/line feed has been encountered. filenum File number of opened file. stringvar Data of which a string variable is stored. LOC ie; A = LOC [ filenum ] filenum Current file number used when opened. Sequential files return a value in 128-byte blocks for either Read or Write. LOF ie; A = LOF [ filenum ] filenum Current file number used when opened. Size of previously opened file in multiples of 128 bytes. 旼컴컴� � 136 � 읕컴컴� LSET & RSET LSET sets the string to left justified, while RSET set it right justified also used to format normal string variables. LSET FIELD-var = stringvar FIELD-var The named String variable as defined in FIELD statement. string-var Name of string to be assigned to FIELD-var. MKD$, MKI$ & MKS$ Numerical expression converted to a string for a Random-access file/s ONLY. A$ = MKD$ [ expression ] expression Constant, numerical or result of a function or calculation. MKD$ A numeric expression in double-precision, converted to 8 byte string. MKI$ Integer expression converted into 2-byte string. MKS$ Single-precision numerical expression which is converted into a 4-byte string. 旼컴컴� � 137 � 읕컴컴� NAME old-file TO new-file. old-file Optional drive & path. Filename of file to be renamed with extension. new-file New filename with extension in either variable or string constant form. Constants must be enclosed in quotes. Strings are not allowed. Error will be given if new-file already exists and will not be over-written. OPEN "drv:\path\file" FOR mode AS # filenum [ LEN = recordlen ] "drv: Drive required. Optional. \path\ Sub-directory name required. Optional. If drv and or \path\ are omitted then you will operate from the current drive and path you are in. file" File name. mode ie; INPUT Open data file to read from. OUTPUT Open data file to write to. APPEND Open in OUTPUT mode but place file pointer at end so it can be extended later on. If no file exists then one is created. 旼컴컴� � 138 � 읕컴컴� filenum The file number that is required by you to perform a function. [ LEN = recordlen ] LEN If LEN is used instead of mode then the file will be opened as a random access file. = recordlen Record length set the total length of the file in bytes. Range from 1 to 32767. OPEN "mode", # filenum,"drv:\path\filenme" [,recordlen] As used and supported in earlier versions of GW-Basic. mode: I Open data file to read with pointer in front of file. O Open data file to write with pointer as above. If file exists then it over-writes that file. A Same as APPEND. R File is opened for random-access operations. filenum File number required by you to read or write to. 旼컴컴� � 139 � 읕컴컴� "drv: Drive required. Optional. \path\ Sub-directory name required. Optional. filenme" File name required. ,recordlen Record length must be stated in mode,R. Length range is from 1 to 32767. PRINT # filenum, exp,....[;/,] To write a data file. filenum A number given by you to write. exp An expression of constants, variables or a result of WRITE# Filenum [SPC(num)] [expression][,] filenum The number to assign to an OPENed file. SPC(number) Write a requested number of spaces. expression Can be variables, constants of resulting calculations. Can take any form. , Tabs line with eight blank spaces before the next item is written. Note ! You can not use the TAB command ! 旼컴컴� � 140 � 읕컴컴� Functions and Calculations. 컴컴컴컴컴컴컴컴컴컴컴컴컴� ; Expresses a constant flow of data. , Expresses add eight spaces between expressions. PRINT# filenum USING "mask"; expres This formats data output to an open file. filenum Number of file required ( after opened ). "mask" See Screen Output for full details. expres The data to be written. Constants, variables calcs or functions. PUT # filenum [,recnum] A file record is written to disk from the defined FIELD and as many characters a predefined by the OPEN command. filenum Number of file required ( after opened ). recnum The record file number to be written. WRITE # filenum [SPC(num)][exp.....][,] filenum Number of file required ( after opened ). SPC (num) NUMber of spaces as specified in num. exp Type of data to be written. Constants, variables etc 旼컴컴� � 141 � 읕컴컴� , Tab output of eight spaces before next item. 旼컴컴� � 142 � 읕컴컴� Error Trapping 컴컴컴컴컴컴컴 ERDEV ie; A = ERDEV Interrupted by MS-DOS error set via INTERRUPT 24 giving low byte. High byte gives bit pattern of device driver that caused error. ERDEV$ ie; A$ = ERDEV$ PRN Error from printer A:B:C Error from Disk. OTHER Error on driver. This actually gives the error name of the device. ERL ie; A = ERL Reports the line number that produced the error. ERR ie; A = ERR Gives the Code Number for the error. ERROR num num Number that you want to use to simulate an error. ON ERROR GOTO linenum linenum The line number that the error trapping routine begins. If a 0 is used then error trapping is turned off and the normal error messages via DOS is displayed. 旼컴컴� � 143 � 읕컴컴� RESUME [linenum/NEXT/0] linenum The line number from which the program is to continue. NEXT Continue the program from the next line down after the error occurred. 0 Similar to RESUME command but without the parameters and the line that produced that error is executed again. 旼컴컴� � 144 � 읕컴컴� Variables and Constants 컴컴컴컴컴컴컴컴컴컴컴� DEF... Allowing several variables in data format. DEFINT from-to Data type as an interger. DEFSNG from-to Single-precision. DEFDBL from-to Double-precision. DEFSTR from-to String. from Global definition of first line. to Global definition of last line DIM varnme (subscripts) [,varnme (subscripts)] Reserve memory for one/multi dimensioned arrays with indexes greater than 10. varnme The array name to be dimensioned. Numeric arrays are defined by %,! # and are appended to the name. Strings have $. subscripts One or more expressions to specify the number of elements and separated by comers. Maximum 255. ERASE var [,var....] To erase one or more predefined variable/s. var Name of array/s to be removed. LET var=val ie; LET A = 10 LET is optional. 旼컴컴� � 145 � 읕컴컴� var Assign a variable value to a variable. val The numeric value of either a variable or numeric expression to be assigned to var. OPTION BASE 0/1 Array indexes are set at lower limits with 0 or 1. 0 Starting indexes of 0 1 Starting indexes of 1 READ and DATA READ var,[var....] ie; READ A, B DATA ["txt"/txt],/val ie; DATA "PETER", 10 Read fixed data values defined from within the program. Can be made into single statements or multi. var Read a variable from a predefined table in DATA. "txt" Data to be read by a string ie; READ A$ txt Data to be read by a string ie; READ, one,two All data types can be mixed providing that they are READ with their corresponding string and variable. 旼컴컴� � 146 � 읕컴컴� RESTORE linenum Reset the DATA pointer to READ from a specified line number. linenum Line number stated. If this is omitted then the pointer is set to the very first DATA line number in the program. SWAP var1, var2 ie; SWAP a$,b$ Both must be the same type. Swaps round the contents of variables around. 旼컴컴� � 147 � 읕컴컴� Command structures 컴컴컴컴컴컴컴컴컴 FOR....NEXT FOR indexvar=startval TO endval[STEP stepwidth]statement(s):NEXT[indexvar] A loop statement which executes until then NEXT command has reached the end of the parameter of endval. indexvar The integer value to hold the value of the loop. startval The start integer value of the loop. endval The maximum range wanted. stepwidth The increment in either positive or minus values. positive values are normal expressions ie; 1,2 etc.. which step through forward. Minus -1, -2 etc, step backwards. statement Supported by GW-BASIC to include any command or function. NEXT [indexvar] Index variable to specify the maximum lines for the loop to execute. EXAMPLE: 100 FOR I = 1 TO 100 : NEXT I (or) 100 FOR I = 1 TO 100 : PRINT "PETER" : NEXT I The [indexval] need not be specified. 旼컴컴� � 148 � 읕컴컴� GOSUB....RETURN ie; GOSUB [linenum] RETURN[linenum] Calls and executes a subroutine and returns to the command line or line number in the program as specified in RETURN. GOTO linenum Branches unconditionally to a line number. linenum Line number that the program is to jump to. IF...THEN...ELSE IF condition THEN statement1 [ELSE statement2] Executes program statements (or branches) based on results of a condition or conditions set. statement1 and statement2 Single or multi statements of commands or functions separated with colons. Total length not to exceed one line. condition Any comparison or condition. ON x GOTO/GOSUB ON index GOTO line number/(s) or ON index GOSUB line(s). This tells the routine to branch conditionally to subroutines or sub-programs via the amount set in the index. 旼컴컴� � 149 � 읕컴컴� EXAMPLE: 100 ON A GOTO 100 or 100 ON A GOSUB 10,20,30 Single or multi indexes. index The integer value of a function, variable or calculation line number/s Line/s separated with commas to branch on value of index. WHILE....WEND WHILE condition WEND As long as a condition is true the statement is executed. condition Logical expression for comparison. EXAMPLE: WHILE A = 10 THEN do this WEND If <> 10 then ignore this expression. 旼컴컴� � 150 � 읕컴컴� Data handling 컴컴컴컴컴컴� = IF this = (equals to) this THEN do this. < IF this is < (less than) this THEN do this. <= IF this is <= (less than or equals to) this THEN do this. > IF this is > (greater than) this THEN do this. >= IF this is >= (greater than or equals to) this THEN do this <> IF this is <> (no equal) to this THEN do this. EXAMPLE: 100 IF A = 10 THEN GOTO 300 200 GOTO 400 300 PRINT "A = 10" : END 400 REM the rest of the program AND ie; IF condition1 AND condition2 THEN do this. The statement is executed if both expressions are true. Same as IF A = 1 AND B = 10 THEN do this. This is a command ... THEN GOTO/GOSUB/RESTORE/RETURN NOT ie; IF NOT condition THEN do this 旼컴컴� � 151 � 읕컴컴� condition Use =, <, >, <>, <=, >= OR ie; IF condition OR condition THEN do this. ASC (expression) Returns a decimal value of an ASCII char. Only first character of a string constant, variable or function is converted. CDBL (expression) This converts a numeric expression to a double-precision value. CHR$(number) Convert numeric value to ASCII character. CINT(expression) Integer value of a numeric value. CSNG(expression) Single-precision value of a numeric expression. DEF FN varname(parm,...) = function FN varname(pram,...) Defines and calls a user defined routine. varname A numerical function that is called with FN parm A parameter of one or more specified variables. function Defines how the variables are used. 旼컴컴� � 152 � 읕컴컴� HEX$ (num) Converts a decimal value to a hexadecimal one. num A number from the range of -32768 to + 65535. OCT$ (num) Converts a decimal value to a string of octal digits. num A constant, numeric value or calculation, or the result of a numerical function in a 16 bit value. RANDOMIZE [NUM] and RND [NUM] Sets a numerical basis for random numbers and generates a random number. NUM can be from -32768 to + 32767. STR$ (express) ie; A$ = STR$(32) Convert a number to a string. Can be a numerical result of a function, a constant etc. VAL (stringexpress) ie; A = VAl (A$) Converts a string (which has numerical contents) to a numeric value. 旼컴컴� � 153 � 읕컴컴� Mathematics 컴컴컴컴컴� Addition (+) result = expression + expression Subtraction (-) result = expression - expression Multiplication (*) result = expression * expression Division (/) result = expression / expression A back slash (\) is used for integer. Exponentiation (^) result = expression ^ expression ABS Absolute value. ie; A = ABS(expression) AND ie; A = B AND C Result if both are set or one is set. ATN ie; A = ATN(expression) Angle of arctangent calculated and return radians in single precision. If Basic/D is used when calling from DOS then double precision is used. COS ie; A = COS(expression) Cosine of an expression is calculated and returns the radians in single precision. If Basic/D is used, then as above. 旼컴컴� � 154 � 읕컴컴� EQV ie; A = B EQV C If two values are combined with EQV then the bits are elevated so that the resulting bit is set providing, B and C are the same. If B and C are not the same, the bit is reset. EXP ie; A = EXP(expression) The constant e is raised to the power of the expression. The result is in single precision. If /D then double precision. FIX ie; A = FIX(expression) This returns the integer portion of the expression. Functions after the decimal point are truncated. IMP ie; A = B IMP C If the combination of the two values B and C are the same, or if B is reset and C is set then the resulting bit is set. INT ie; A = INT(expression) The expression is returned with the greatest integer value. LOG ie; A = LOG(expression) The expression is returned with the natural logarithm. MOD (modulo) ie, A = expression MOD expression Gives the remainder of an integer division. 旼컴컴� � 155 � 읕컴컴� NOT ie; A = NOT Y Sets each bit in Y if either set/reset depending on the action taken before calling. XOR ie; A = B XOR C If both B and C are equal then bit is set. The resulting bit is set only if either B or C is set. SGN ie; A = SGN(expression) Returns the sign of the expression. +1 for positive, -1 for negative and 0 for equal to zero. SIN ie; A = SIN(expression) The sine of the expression is calculated in a single precision radians. If /D is used the double precision. SQR ie; A = SQR(expression) Square root of the expression in single precision. If /D then as above. TAN ie; A = TAN(expression) Returns the tangent of the expression in single precision. If /D then Double precision. 旼컴컴� � 156 � 읕컴컴� Screen output 컴컴컴컴컴컴� CLS Clear screen and place cursor to top left of the screen. COLOR [text col],[background] Set up screen's text and background colours. NB!!! Colour Cards: CGA card only allows selections between 0 and 7 while EGA cards allow 0 to 15. Composite: The colours are in shades of gray and some combinations will not be suitable to read. text col A value between 0 and 15 to set charactr colours. background A value between 0 and 7 to set background colour. 旼컴컴� � 157 � 읕컴컴� Monochrome Monitors 컴컴컴컴컴컴컴컴컴� Normal COLOR 7,0 Double Intensity COLOR 15,0 Underline COLOR 1,0 Reverse Video COLOR 0,7 Flashing COLOR 31,0 Colour 컴컴컴 0 Black 1 Blue 2 Green 3 Cyan 4 Red 5 Magenta 6 Brown 7 Light Gray 8 Dark Gray 9 Light Blue 10 Light Green 11 Light Cyan 12 Light Red 13 Light Magenta 14 Yellow 15 White You can add 16 to the text colour value which causes it to flash. CSRLIN ie; A = CSRLIN Gives the current cursor position. LOCATE [line][,column][,1 (on/off) 2][,fromln][,toln] Sets the cursor position on the screen, turns it on or off and sets the cursor shape. 旼컴컴� � 158 � 읕컴컴� line The Vertical position between 1 anD 25. column The horizontal position on a line between 1 and 80 or 1 and 40 depending on the screen type. on/off The cursor can be switched on or off. 1=on and 2=off. fromln, toln The cursor can have a number of shapes depending on the monitor and card you are using. The top line is 0 while the bottom line can be up to 31. For Composite and colour it is 0 to 7, while Monochrome is 0 to 31. POS(0) ie; A = POS(0) Shows where the cursor is located by column. SCREEN [mode][,colour][,page][,display] To set text mode and colour and selects display pages. mode In which operating mode the screen is to operate. 0 text mode 80 x 25 or 40 x 25 1 graphics mode 320 x 200 pixels 2 graphics mode 640 x 200 pixels x graphics mode 640 x 400 pixels for version 2 and mono cards. colour Colour remains the same if set to 1. If set to 0 then text colour is light gray and bagkground is black. 旼컴컴� � 159 � 읕컴컴� page There are 4 pages available (0 to 3) on 80 x 25. There are 8 pages for the 40 x 25 monitors. display To actually display a page. Same selection as above. SCREEN ie; A = SCREEN(line,column[0/1]) The ASCII value (code or attribute) is returned from a position on the screen. line, column The position of the character of the screen. Values of 1 to 80 or 1 to 40 depending on monitor type. 0/1 0 for the ASCII code or 1 for the colour code. VIEW PRINT [fromln] [TO] [toln] This command defines the size of a text window. fromln , toln Only full lines can be displayed. The range of line numbers is 1 to 25. WIDTH numchars To state a number of characters to be displayed on output. numchars States either 40 or 80 column. Use 40 or 80. This command will clear the screen before setting the width. 旼컴컴� � 160 � 읕컴컴� PRINT [TAB(column)][SPC(num)] [expression....][;][,] This displays to screen. column A value of between 1 to 80 or 1 to 40 depending on the width of your screen. A horizontal position on one line. num A number of spaces specified. expression The type of data to be printed. ; Suppress the carriage return and print next statement directly after the one just printed on the same line. , Print next character 8 places along on the same line. PRINT USING mask; expression A user formatted data display. mask A string variable or constant to set formatting the characters oN the screen. expression Data type to be printed. Can be constants, variables etc. Numerical data MASK type: "#####" Each hash(#) represents a digit. If a sign is required then an extra hash is added. Numbers are rounded off before being printed. 旼컴컴� � 161 � 읕컴컴� "#####.##" Decimal places. "+#####.##" A plus before or after will display the sign either "#####.##+" before or after the result. "#####.##-" A minus sign will display the negative value only. Positive values are without signs. "#####.##^^^^" An Exponential expression is displayed. "**#####.##" If the value is less than the digits required then the asterisks are printed in front of the displayed value. "$$#####.##" The dollar sign will place a dollar in front of the displayed value. Can not be used with ^^^^ and if preceding asterisks then only the dollar will be printed. "#######,.##" Comma which has been incorporated will display in groups of three digits separated with commas. String data MASK types: "\ \" Number of characters to be printed depending on the amount of spaces in between the back slashes(\). "&" Print the string as unformatted. 旼컴컴� � 162 � 읕컴컴� "!" Print only the first letter of a string. "_" (underline) Everything preceeding the underline is not formatted. This is allowed for those characters which are not normally included in the mask rules. "#####.## text" The text is printed relative to the print. ; Used to separate an expression from a mask and visa-versa. WRITE [SPC(num)]["expression....."][,] Prints output to screen. SPC(num) Print a specified number of spaces on current line. expression The type of data to be printed. ' Print 8 characters along on the same line. The TAB and semicolon (;) can not be used with WRITE. 旼컴컴� � 163 � 읕컴컴� Graphics 컴컴컴컴 CIRCLE[STEP] (out_x,out,y),radius[,pen_col] [,arc_str,arc_end] [,axes_ratio] To draw an ellipse or a circle on a graphic screen. out_x,out_y The absolute coordinates of a circle or ellipse used with out the STEP specifications. STEP specifies the position relative to the last point on the screen. Y range from 0 to 199 and X range from 0 319 or 639 depending on the type of screen you have. radius The radius of a ellipse or circle. arc_str,arc_end The starting and ending points. Values are angles in radians. Values from -2 pi to +2 pi. COLOR [foreground][,background][,text_colour] Sets a high-resolution graphics screen mode (640x200 points). foreground Both text and graphic colours. Range 0 to 15. background Default value is set to black. High-resolution is for monochrome and some conversion is necessary: 0 Black 1 White 2 Black 3 White 旼컴컴� � 164 � 읕컴컴� COLOR [background][palette][,graf_back][,graf_fore] [,text_col] Set medium-resolution graphics mode (320x200 points). background Set colour of entire screen. 0 to 15. palette One of two palettes to be set: 0 colour 0 = background 0 colour 1 = green 1 colour 0 = background graf_back,graf_fore Standard values of drawing colours used in graphic commands depending on palette last used. text_col Based on the palette used, specifies the text colour. The value of '0' cannot be used. DRAW string Draws a graphic as set out by a string. string Can be a variable, constant, or a result of a string expression. The current position at which DRAW will begin, either the centre or the last position used. PSET must be set before the DRAW command can be issued. The string can be set by using the following: U num To draw a number of points up. D num Down. 旼컴컴� � 165 � 읕컴컴� L num Left. R num Right. E num Diagonally to the right. H num Diagonally to upper left. F num Diagonally to lower right. G num Diagonally to lower left. The variable within the string must have equals sign (=) before it and a semi-colon after it. B dir Move the pen one point without drawing. The dir uses U,D,L,R,E,F,G or H. N dir Move the pen one point in any given direction. M,X,Y If X,Y are not preceded with a plus or minus sign, then the line is drawn from the current point. C Set the drawing colour. P,F,B Fill a position enclosed by border color B and fill it with color F. P does not have any parameters and must be used. A angle Set the angle of movement. ie; 0= 0 degrees, 1 = 90, 2 = 180, 3 = 270 and so on. TA angle Angle of movement. Range -360 to +360. 旼컴컴� � 166 � 읕컴컴� S factor To return a value from the formula factor/4 that should be multiplied with all the numerical parameters for movement to follow. This allows objects to be drawn to scale with one another. Range from 0 to 255. X string_var; To store often repeated procedures. GET [STEP] (X1,Y1)-[STEP] (X2,Y2), array Stores graphics in an array so that they can be stored onto a diskette or moved onto the screen. STEP (X1,Y1),STEP(X2,Y2) X1,Y1 are values of the lower left corner and X2,Y2 are for the upper right corner to be stored. Y range up to 199 while X can be up to 319 or 639 depending on the resolution selected. array Must be previously dimensioned with DIM of which the size is to be stored. Size can be calculated by the following: A = 4+INT((pointX * B+7) /8) * pointY A = 1 for 640x200 resolution. A = 2 for 320x200. pointX = width of graphic in pixels. pointY = height of graphic in pixels. 旼컴컴� � 167 � 읕컴컴� LINE [STEP] [(fromX,fromY)]-[STEP](toX,toY) [draw_col][B,[F]] [,raster] To draw rectangles and lines. fromX,fromY The starting coordinates of the lines be drawn. If the STEP command is not stated then the absolute value is taken as the starting point. STEP fromX,fromY puts the point relative to the last address position on the screen. X range 0 to 39. Y range 0 to 639 depending on the resolution of the screen. For a rectangle, this is the bottom left. toX,toY The ending point of a line. Y range 0 to 199 and X range from 0 to 319 or 639 depending on resolution. For a rectangle, this is the upper right corner. draw_col The colour of the line to be drawn. Range 0-3. B To draw a rectangle. F If F follows a B then the rectangle is filled in with the colour specified in COLOR command. raster Normally a solid line is shown, but the appearance can be changed with a 16 bit mask. LINE This converts the coordinates outside the defined SCREEN area to prevent the program terminating in a error. 旼컴컴� � 168 � 읕컴컴� PAINT[STEP] (X,Y) [,mode] [,border_col] The enclosed area is filled with a given colour or pattern. (X,Y) The absolute coordinates of a point. With the STEP command; last relative position on the screen. Y range 0-199 and X range 0-319 or 639 depending on the screen resolution. mode Colour or pattern an area. If COLOR has a value of from 0 to 3 then that colour is used. If not, you can make a 8x64 bit mask (64 bytes) as a pattern. The pattern is specified with CHR$. border_col The surrounding area of the region to be filled. Colour is set by border and ranges from 0 to 3. PMAP ie; A = MAP(coordinate),mode Assigns a variable with the changed coordinate assigned with WINDOW. coordinate X or Y converted coordinate according to mode. mode=0 X coordinate is set with WINDOW and converted to an absolute coordinate value. mode=1 Y (as above). mode=2 An absolute X coordinate which is converted to an axes set with WINDOW. mode=3 Y (as above). 旼컴컴� � 169 � 읕컴컴� POINT ie; A = POINT (X,Y) Assigns a variable with the point colour at a given coordinates. (X,Y) The coordinates being tested. The returned colour value is between 0 and 3. A 0 Coordinate of X 1 Coordinate of Y 2 World coordinates of X 3 World coordinates of Y PRESET [STEP] (X,Y) [,draw_col] A specified point is cleared from the screen. (X,Y) The absolute coordinates or if specified with STEP, will be the position of the last relative point. Range of Y, from 0 to 199 and X between 0-319 or 639 depending on the resolution of the screen. draw_col The point colour. If omitted, the point will be in background colour. Range 0-3 PSET [STEP] (X,Y) [,draw_col] Set a point at a specified coordinates. STEP Relative position of the last position on the screen. Without STEP, gives the absolute position. 旼컴컴� � 170 � 읕컴컴� (X,Y) Y range between 0-199, X range 0-319 or 639. draw_col To specify the actual point colour. 0 to 3. PUT (X,Y),array [,mode] With the GET command, will display a graphic stored in an array. (X,Y) Upper left point. array The array that contains the graphic. mode States how the stored graphic is to de displayed. 旼컴컴� � 171 � 읕컴컴� Mode commands 컴컴컴컴컴컴� PSET Output exactly as read. PRESENT Invert the graphic ( in reverse ). XOR The point is inverted one way or the other, depending on how it is displayed. AND The point is ANDed. OR The point is ORed. See mathematics for more descriptions. SCREEN [mode][,colour][,output_page] [,display_page] Set the graphics mode and resolution. Mode commands: 0 Text. 1 Medium resolution. 2 High resolution. 100 Special modes for other cards. colour When the SCREEN is called and color=1, then the colour is retained. But, if color=0 the default colours are set. Default colours: Black background and white foreground. 旼컴컴� � 172 � 읕컴컴� output_page,display_page In graphics mode there is only one page. Parameters are ignored. VIEW [SCREEN](X1,Y1)-(X2,Y2)[background_col] [,border_col] The size and colour of the window to be displayed. (X1,Y1)-(X2,Y2) Defines the lower left and upper right corners of the window. background_col Background colour of the window. 0-3. boarder_col Border colour of the out side of the window. WINDOW [SCREEN](X1,Y1)-(X2,Y2) This command defines the coordinate system to be used for the current window, and is normally in world coordinates. World coordinates start a 0,0 for the centre of the screen. The X value above the centre are positive and below are negative. The Y values to the right of the screen are positive and to the left are negative. (X1,Y1) The upper left corner. (X2,Y2) the lower right corner. 旼컴컴� � 173 � 읕컴컴� Getting input from the keyboard 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� INKEY$ ie; A$ = INKEY$ NOTE! same as commodore GET$. Inputs an ASCII character from the keyboard in a two byte form. The first byte is 0 while the second contains the ASCII value. To get special functions keys you will have to determine the LEN of that string, that being two, and then work on the right$. The cursor is set in the OFF state. Can be switched on by using the third parameter of LOCATE. 1 = ON 0 = OFF. INPUT [;]["mess"];/,var,.... ; Line feed will be suppressed if added. "mess" A text message that prompts for an answer. , Suppresses the quotation mark. var Variable/s used to store values. ie; A or a$ etc.. INPUTS$ ie; A$ = INPUT$ (numchars) Characters specified to be read from the keyboard. numchars Number of characters to be read from the keyboard. LINE INPUT [;]["mess"];/,stringvar One line read from the keyboard. 旼컴컴� � 174 � 읕컴컴� ; Line feed is suppressed. "mess" Text prompt. , Suppress the question mark. stringvar A single string variable input. 旼컴컴� � 175 � 읕컴컴� String handling 컴컴컴컴컴컴컴� + ie; A$ = string1 + string2........ Concatenates strings. string Variable, constant or the result of a function. Total length of characters is 255. DATE$ and TIME$ A$ = DATE$ Variable set to current date. DATE$ = A$ Date changed to value of A$. ie; DATE$ = "mm-dd-yy" month, date, year. Same procedure for TIME$. ie; TIME$ = "hrs:min:sec[hsec]" DEF FN stringnme(parm...) = function FN stringnme(parm) DEF FN is used to define a function of a string while FN on its own is used to call that function. stringnme Name of a string variable when called. parm One or more string$. function Parameter operation performed. The DEF FN function must be defined first, then called with FN. 旼컴컴� � 176 � 읕컴컴� FRE("") Clears up the string storage area for garbage collection. INSTR ([frompos],string,searchchar) To search and return the position of a certain character from within a string. frompos Numerical expression requesting the start position for the search to begin from within the STRING. If omitted, search begins from the first character. string The string or element of a string array to be searched. searchchar A character string of constant, variable or result. LEFT$ ie; A$ = LEFT$(string,numchars) Returns the result of the leftmost part of a string. string String or elements of an array to be dissected. numchars Number of characters to be returned. LEN ie; A$ = LEN(string) Returns the length of the whole string or array. MID$ ie; A$ = MID$(string,firstchar[,numchar]) Returns a number of characters beginning at a given position. 旼컴컴� � 177 � 읕컴컴� string A string or array to be dissected. firstchar Number of characters to be returned. MID$ (deststring,firstchar[,numchars]) = srcstring Replace one section of a string with another. deststring String or array to be replaced. firstchar The destination character string where the source string is to be inserted. numchar Number of destination characters to be replaced. srcstring Start to replace source characters starting at the firstchar. RIGHT$ ie; A$ = RIGHT$(string,numchars) Returns the rightmost number of characters of a string. string String or array to be dissected. numchars The rightmost number of characters that are returned. SPACE$ ie; A$ = SPACE$(number) Returns a string with the number of spaces as specified. number Specified number of spaces. 旼컴컴� � 178 � 읕컴컴� STRING$ ie; A$ = STRING$(number,char) Returns a specified number of single characters in a string. number Specified number of characters to be repeated. char A constant, variable or result of a string function to be repeated. 旼컴컴� � 179 � 읕컴컴� Printer output 컴컴컴컴컴컴컴 LCOPY (num) This command is not included in all Basics. It prints the screen to the printer. num Depending on Basic version, usually 0. Some PC's have a program called GRAPHICS.COM which will allow a graphic screen to be printed when you press Shift-PrtSc. This must be called first. LCOPY only works in text mode. LPOS ie; A = LPOS(printernum) 'A' is returned with the position of the buffer pointer. printernum The interface number, 1,2 or 3. Default is 1. LPRINT[TAB(column)][SPC(num)][expression....] [;][,] This command will print your data to the printer. column The printer tab position (horizontally) in numerics and must be set first, if required. num The number of spaces. expression Data to be printed which can be constants, variables etc. Data can be separated with a ';' (semicolon) to suppress line feeds, thus allowing multiple expressions on one line. 旼컴컴� � 180 � 읕컴컴� Data with a ',' (comma) forces a tab of 8 character positions. The printer can be opened as a file for output. ie; OPEN "LTPx:" FOR OUTPUT AS #1 : PRINT #1,A$ The device number (x) can be 1,2 or 3 and the file must be closed when you have finished with it. LPRINT USING "mask";expression Formats the output to the printer by using the "USING (mask)" expression. See Screen Output for 'mask' details. expression The type of data to be printed. WIDTH LPRINT numchars or WIDTH "LPT printernum;",charnum Used to set the number of characters to be printed. numchars The number of characters to be printed before a linefeed given a range from 0 to 255. The default is set to 80. printernum Printer interface number, 1,2 or 3. 旼컴컴� � 181 � 읕컴컴� Techniques in using the Interrupts 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 KEY keynum,CHR$(toggle/shift)+CHR$(scancode) This command defines a key, or combination of keys to perform certain tasks by using the ON KEY statement. keynum Specify a values from 15 to 20. toggle/shift: Depends on the keyboard driver of your machine. CTRL 04 (decimal) or &H04 (hexadecimal) ALT 08 &H08 NUMLOCK 32 &H20 SHIFT 64 &H40 scancode This very much depends on the driver used. When the key is depressed, a value (not ASCII) is given. It is those values you are looking at. See your computer manual. If KEY (keynum) STOP is used, the routine is not executed for that 'keynumber'. However, the flag is set for the next KEY() ON and if encountered, that routine is executed. KEY (keynum) STOP command is used to prevent an infinite loop. Use RETURN at the end of the routine. If you are using the ON ERROR GOTO command, error handling will suspend the key interrupt. The command RESUME will restore it. 旼컴컴� � 182 � 읕컴컴� To stop the key interrupt from re-enabling, use KEY() OFF for the KEY(keynumber) routine required. ON COM channel GOSUB linenum COM channel ON/OFF/STOP If a byte is read during the interrupt, the serial interface will execute a routine. channel A number of 1 to 4 depending on interfaces. linenum The line number of the routine to be executed. COM channel ON Switch on the interrupt checking. COM channel OFF Switch off the interrupt checking. COM channel STOP Stop checking until next channel ON command. ON KEY(keynum) GOSUB linenum KEY(x) ON/OFF/STOP This function reads the desired interrupt key and executes the routine given by the line number. keynum F1 to F10 1 to 10 Cursor up 11 Cursor left 12 Cursor right 13 旼컴컴� � 183 � 읕컴컴� Cursor down 14 linenum The line number of the routine that is to be executed when the key is depressed. KEY(keynum) ON Switch on the interrupt for checking key/s. KEY(keynum) OFF Switch off interrupt. KEY(keynum) STOP Stops the interrupt checking until the next command of KEY(keynum) ON is found. ON PLAY (num_notes) GOSUB linenum PLAY ON/OFF/STOP Checks the number of notes when then PLAY buffer is checked. If the number of notes is less or equal ( <= ) to num_notes, then the appropriate routine is executed. Can be used to play music in the background. num_notes Total number of notes still remaining in the buffer which is to be executed by the routine required. linenum The line number at which the routine starts. PLAY ON Switches the interrupt on for checking. PLAY OFF Switches the interrupt off. PLAY STOP Switches the interrupt off until the next PLAY ON. 旼컴컴� � 184 � 읕컴컴� ON TIMER (seconds) GOSUB linenum TIMER ON/OFF/STOP Depending on the time specified and the result, the interrupt is read and the routine starting on (line number) is executed. seconds A value of 1 to 86400 for which an interval is given so that a routine can be executed at a line number specified. linenum The line number at which a routine is to be executed. TIMER ON Switch on the interrupt for checking. TIMER OFF Switch off the interrupt. TIMER STOP Stops the interrupt checking until then next command of TIMER ON is found. 旼컴컴� � 185 � 읕컴컴� Machine Code 컴컴컴컴컴컴 CALL [S] offset_var[,data_var] This calls a machine code program which has been POKED into memory or BLOADed from a drive. [S] CALLS is also known as CALL which places the current segment onto the stack in low byte/high byte form. Compilers are required to pass the segmented address. offset_var The address at which the routine begins. This is a integer value which must be set with DEF SEG before called. data_var Data or values to be processed are passed to the routine by variables. A 2 byte offset pointer of the contents of the variable is placed on the stack in low/high order and is processed from there. DEF USR and USR ie; DEF USR number = offset Called with USR number = [data_var] DEF USR sets the offset variable while USR calls the machine code routine which has been POKED or BLOADed into memory. number A value between 0 and 9 of which one or more routines is numbered. They are called by USR (required routine). offset The offset address at which the routine starts. The segment must be defined with DEF SEG at the start. 旼컴컴� � 186 � 읕컴컴� data_var Variables whose contents are to be processed. The value is loaded into the CPU registers: AL contains: &H02 integer, &H03 string, &H04 single precision &H08 double precision. BX contains: The offset pointer to the FAC where the numerical value is stored. DX contains: A 3 byte area that contains the length of the string in the first byte, and the offset address of the string in the next 2 bytes. These are in the form of a low/high. 旼컴컴� � 187 � 읕컴컴� Sound commands 컴컴컴컴컴컴컴 BEEP A single note is executed. PLAY string A set of notes is played depending on the string. string This can contain the following: MF(mode foreground) Notes to be in the foreground. MB(mode background) A maximum of 32 notes for background. MN(mode normal) Normal length notes. 7/8 of length as specified in the string by L. ML(mode legato) Smooth tones as specified in the string by L. MS(mode staccato) Short notes. 3/4 of length, specified in the string by L. Ox(octave) Set the octave. Range from 0 to 6. > Raise tone by an octave. Maximum of 6. < Lower tone by an octave. Minimum of 0. A to G[-][+/#] Musical tones from A to G. The + or # sign rises the tone by half (sharp). The - sign lowers it (flat). 旼컴컴� � 188 � 읕컴컴� N note_num One of 84 notes from within each seven octaves. The range is 0 to 84. The 0 produces a reset. P note_length This produces a rest between notes and can be range from 1 to 64. Each note length is 4 giving a quarter. L note_length The length of notes. Range of 1 to 64. If L with a parameter follows a note then it only applies to that note. T tempo The number of quarter notes per minute. 32 to 255 . The full stop causes the tone to run one and a half times faster than the values set in L and T. X string_var; Executes a designed string. ie; "T = Tempo;" SOUND frequency, duration frequency The pitch to be created. Range, 37 to 32767. duration Length of tone measured in clock ticks. 0 to 65535. 旼컴컴� � 189 � 읕컴컴� Memory accessing 컴컴컴컴컴컴컴컴 BLOAD filespec, offset Loads a file into a given memory area. filespec The [drive\path\] filename of the file to be loaded. offset The address as specified with the DEF SEG command used at the beginning of the program or routine. Data is read until an EOF character (&H1A) is read. BSAVE filespec, offset, num_bytes Saves a given area in memory to the diskette. filespec The [drive\path\] file name to be loaded. offset The address to be saved as set by DEF SEG. num_bytes The number of bytes to be saved from the offset. DEF SEG = segment_address Used for BSAVE, BLOAD, PEEK, POKE, VARPTR and VARPTR$. segment_address The segment referred to commands and functions with the possible ranges from 0 to 65535. If this is not specified then the data segment (DS) currently occupied by Basic is set as 旼컴컴� � 190 � 읕컴컴� the default. Basic does not check to see if the selected segment is occupied. PEEK ie; A = PEEK(offset) This returns an 8 bit value of the specified address (offset) in the current segment. offset The address in the range of 0 to 65535. POKE ie; A = POKE offset,value This command will write a value into memory. offset The memory address within the segment. 0 to 65535 value A numeric value to be written to the location. 0 to 255 VARPTR ie; A = VARPTR(variable) or A = VARPTR(# file_num) Determines the offset of a variable in a data segment (DS). variable A variable can be any type including arrays, but must be assigned first before this function is called. file_num The file number that has been opened. This returns the address of the first byte of file control block (FBC) for sequential files. Random files return the first byte of the FIELD buffer. 旼컴컴� � 191 � 읕컴컴� VARPTR$ ie; A$ = VARPTR$(variable) The variable type and offset is determined by the variable in the data segment (DS). The first byte of the string contains the information of the type of variable: CHR$(2) is an integer CHR$(3) is a string CHR$(4) is single precision CHR$(8) is double precision The second and third bytes contain the address of the first byte of the variable (low byte/high byte): address = low byte + 256 * high byte variable A variable can be any type including arrays, but must be assigned first before this function is called. It is important to note, that garbage collection will change the addresses of the variables. 旼컴컴� � 192 � 읕컴컴� I/O Communications 컴컴컴컴컴컴컴컴컴 GET# file_num,num_chars Gets a specified number of characters from the serial interface into the communications buffer. file_num The file number used in the OPEN command. num_chars The number of characters to be read. Cannot be longer than the record length. INP ie; A = INP (port) . Port value 0 to 65535 Reads the current value of a control or data port. LOC and LOF ie; A = LOC(filenum) A = LOF(filenum) Return the number of characters in the transfer buffer that has been read. filenum The file number used in the OPEN command. OPEN COM OPEN "COM channel:[baud][parity][,word with][,stop bits][,RS] [,CS[time]][,DS[time]][,CD[time]],[BIN] [,ASC] [,LF]" [FOR mode] AS #[filenum] [LEN=length] This opens and initialises the serial port for communications. 旼컴컴� � 193 � 읕컴컴� channel The interface number. Normally 1. baud rate To set the number of bits per second for data transfer. Possible values are 75, 110, 150, 300, 600, 120, 1800, 2400, 4800, 9600 parity Data transfer parity. Normally set to N (no parity). These abbreviations can be used: N no parity E even parity U odd parity S space M mark word width The number of bits per character. Default is 7. stop bits The number of bits sent after each character. Unless stated, this is normally set for 2 bits if the baud rate is less or equal ( <= ) to 110. RS This command suppresses the Request to Send (RTS) command during transmission. CStime Waits for a Clear To Send (CTS) signal from the device. 旼컴컴� � 194 � 읕컴컴� DStime Waits for the Data Set Ready (DSR) signal from the device. CDtime Waits for the Carrier Detect (CD) signal from the device. BIN The data received is to be treated as binary. CR and LF and EOF are not interpreted, therefore not used. ASC Received data as ASCII. LF A line feed command is to be sent after carriage return. mode Sets transfer mode: INPUT=receive OUTPUT=send The FOR mode should be stated otherwise the data will be sent in at random, therefore allowing simultaneous input and output. file_num The file number for input/output. 1 to 15 max. length The length of data to transfer. Default is 255 for INPUT and 128 bytes for OUTPUT. OUT port,value Writes a value to a control or data port. port A value of between 0 and 65535 for data to write. value A single value from 0 to 255. It is suggested that you read up on I/O communications from other sources. 旼컴컴� � 195 � 읕컴컴� PUT# filenum,numchars Write a number of characters from the buffer to the interface. Same parameters as GET. Data is written into the buffer using the commands PRINT#, WRITE# and PRINT# USING. WAIT port,mask1,mask2 Stop a program until a given bit pattern is read from the port. This can create an infinite loop which CTRL/C or CTRL/Break can not get out of. The value read from the port is combined with the masks: ie; read value XOR mask1 AND mask2 If the result is zero the port is read until the result is not equal to ( <>) zero. port A value between 0 and 65535. mask1,mask2 Values used to make up a formula. WIDTH "COM channel:";num_chars To set the number of characters sent before a CR is sent. channel The serial port being addressed. Normally one is only installed, so the default is 1. There can be 1 to 4. num_chars The number of characters to be sent. 旼컴컴� � 196 � 읕컴컴� ERROR MESSAGES 컴컴컴컴컴컴컴 01 NEXT without FOR As the program has ran it encountered a NEXT command that did not have FOR statement to execute it. ie; FOR I = 1 TO 100 : NEXT 02 Syntax error A keyword that was entered has a typing error, was an illegal command not supported in Basic, simply forgot commas, semicolons or there are too many characters in a line. 03 RETURN without GOSUB A RETURN command was encountered before first executing a GOSUB command. ie; 100 FOR I = 1 TO 100 110 RETURN 120 NEXT I 04 Out of data The command READ attempted to read more data than was available in the DATA statements. ie; 100 FOR I = 1 TO 3 : READ A : NEXT Rest of program here. 500 data 255, 13 旼컴컴� � 197 � 읕컴컴� 05 Illegal function call * GET# or PUT# for a random access file is 0 * Using a USR command without defining the DEF USR * A mathematical value was illegal * An illegal parameter was passed to a function * An array was index with a negative number 06 Overflow The calculation preformed was too large. 07 Out of memory The program was to large to fit into memory, or that there is not enough memory for variables. Also, too many nested FOR/NEXTs WHILE/WENDs, and GOSUBS/RETURNs. Use FRE("") to perform garbage collection. 08 Undefined line number A line number that is being referred to does not exist. 09 Subscript out of range An array being addressed has not been defined with a DIM statement or that the array is larger than that defined DIM statement. Also if lower than the boundary set by OPTION BASE. 旼컴컴� � 198 � 읕컴컴� 10 Duplicate definition An array has already been dimensioned using the DIM() statement. To re-dimension, use ERASE first. OPTION BASE must be used at the very beginning of the program before the DIM statements. 11 Division by zero An attempt was made to divide a value by 0. 12 Illegal direct A program command was used in direct mode. 13 Type mismatch Variables in a mathematical operation do not match. 14 Out of string space An overflow has occurred because too many string operations have been used. Use garbage collection with FRE(""). 15 String too long A string (ie; A$) or a combination of strings can not exceed 255 characters. 16 String formula too complex A string operation has proved to complex for the Basic interpreter and therefore needs to be split into smaller operations. 旼컴컴� � 199 � 읕컴컴� 17 Can't continue If a program has stopped with the STOP command or has been changed in some way. 18 Undefined user function DEF FN or DEF USR has not been defined before using a FN or USR function. 19 No RESUME The error handling routine did not contain a RESUME command. 20 RESUME without error Within the program line a RESUME was encountered and an error had not been encountered. 22 Missing operand An operand within an operation is missing. 23 Line buffer overflow A line number length was longer than 255 characters. You will have to split it up into 2 lines 24 Device timeout An answer was not received from a device. Check that it is switched on, or connected. The error can be trapped with the ON ERROR GOTO command and use IF ERR = 24 THEN RESUME 旼컴컴� � 200 � 읕컴컴� 25 Device fault The device called for an operation does not exist. 26 FOR without NEXT The NEXT command is missing from a FOR loop/s. 27 Out of paper The printer has sent an "out of paper" error code. 29 WHILE without WEND The WHILE operation has a missing WEND statement. 30 WEND without WHILE The WEND statement has a missing WHILE operation. 50 FIELD overflow A field was made larger than the actual file length as specified in the OPEN command. 51 Internal error The Basics Interpreter has made an error within its self. 旼컴컴� � 201 � 읕컴컴� 52 Bad file number A file that you try to access has not been opened, or is out of range ( 1 - 15). It is possible that you have already opened the maximum range of files. 53 File not found The file that you require can not be found. In most cases it is possible that you have omitted the drive\path. 54 Bad file mode You tried to operate a device with the wrong command. 55 File already open A file that you required to OPEN is already open. You should CLOSE # file_number after all operations. 57 Device I/O error An error has occurred while an operation was being performed on and device. If it is the hard disk, then there could be a problem. If on the printer, the paper may have run out, or the machine has been switched off. If the floppy disk, then it may be that the diskette has not been formatted, or that it is write protected, or for some other reason. 旼컴컴� � 202 � 읕컴컴� 58 File already exists In changing the name of your file, you have tried to name it with the same name. 61 Disk full There is no more space to store programs. 62 Input past end While reading a file, you have gone past the end. Use the EOF operation to check for the end of file. 63 Bad record number The requested record number is 0 or greater than 16,777,215 64 Bad file name The file name used has either to many characters or illegal characters. 66 Direct statement in file Basics require line numbers except most compilers. While the file was being loaded, it found a line number missing. To add line numbers use an ASCII editor (if saved with the ,A) or EDLIN. 67 Too many files The directory of the disk has too many files. You will have to use another dish/ette. 旼컴컴� � 203 � 읕컴컴� 68 Device unavailable The device being accessed with an OPEN is nonexistent. 69 Communication buffer overflow The buffer for the COM interface has exceeded its capacity. You can set it using the Basic/C: buffer 70 Disk write protected The diskette has a write protect tab on it. Depending on the operation, you may leave it on or take it off. 72 Disk media error * The diskette has something physically wrong with it. * The Read/Write head cannot be positioned correctly. * Defective sectors have been found. * The Read/Write head is dirty. Use CHKDSK.COM to check out the diskette and also try to copy the files to another diskette. 74 Rename across disks You cannot specify other drives while trying to rename a file. 旼컴컴� � 204 � 읕컴컴� 75 Path/file access error A given file or path contains an error. 76 Path not found The path requested for a file is not correct 旼컴컴� � 205 � 읕컴컴� USEFUL TIPS 컴컴컴컴컴� Special Keys:: Using PEEK and POKE. Address &H40 with offset &H17. ALT = 8 CTRL = 4 BREAK = 16 NUM/LOCK = 32 CAPS/LOCK = 64 INS = 128 Left SHIFT = 2 Right SHIFT = 1 Combinations of keys are:- Left SHIFT + Right SHIFT = 3 CTRL + Left SHIFT = 6 CTRL + ALT = 12 CTRL + Right SHIFT = 5 ALT + Left SHIFT = 10 ALT + Right SHIFT = 9 INS + NUM/LOCK = 160 (INS first then NUM/LOCK = on, reverse = off) NUM/LOCK + CAPS/LOCK = 96 NUM/LOCK + CAPS/LOCK + BREAK = 112 These are some of the combinations that can be had. 旼컴컴� � 206 � 읕컴컴� Monitor type 컴컴컴컴컴컴 DEF SEG=0:A=PEEK(&H410) AND &H40:DEF SEG 'A' holds the value for the monitor type being used. 1 = 40 x 25 Colour 32 = 80 x 25 colour 48 = Mono 64 = both colour and mono. As with the programs in this book, it is simpler to say:- IF A = 48 THEN DEF SEG=&HB000 ELSE DEF SEG=&HB800 Memory (RAM): DEF SEG=0:A%=PEEK(&H413) + (256* PEEK(&H414)):DEF SEG A% now holds the amount of memory. You can now display the amount of actual memory by PRINT A% wherever you want on the screen. DOS keyboard fonts: If you have used the English keyboard set and want to return to the American keyboard, then press CTRL/ALT/F1 together. To get back to the English keyboard press CTRL/ALT/F2 together. 旼컴컴� � 207 � 읕컴컴� Screen locations 컴컴컴컴컴컴컴컴 For characters, the locations are EVEN numbers. 0,2,4,6 etc; while the colour for each character is held in the odd numbers. 1,3,5,7 etc;. Therefore, a character in position 0 will have it's colour in position 1. A character in position 2 will have the colour in 3 and so on. Remember to find out what monitor is being used first and set a variable to that value (as in the section 'monitor type'.) Type in this routine and see what I mean. I am only going to do this for 80 coloum machines. 1 CLS:KEY OFF:DEF SEG=0:AA=PEEK(&H410) AND &H40 Clear the screen. Set to look at Monitor type. Set the variable 'AA' to look at the monitoe type. Now 'AA' holds a value. 2 IF AA=48 THEN DEF SEG=&HB000 ELSE DEF SEG =&HB800 If the variable AA is 48 then it is a Mono screen ELSE it is a colour one. 3 A=160:B=240:FOR I=0 TO 80 STEP 2 The variable 'A' is set for the last character position of the screen. 'B' is set to last character position in the screen line two. We do a loop from 0 to 80 stepping over every ODD number. Remember, ODDs are for colour attributes. Here we want to poke onto the screen a character first. 4 POKE I,219:POKE 3840+1,219 We poke an Inverted space character (ASCII 219) onto 旼컴컴� � 208 � 읕컴컴� the screen every even number. We also Poke the same character onto the bottom line of the screen. 5 IF B<3770 THEN POKE A,219:POKE B,219:A=A+160: B=B+160 Providing we have not gone over a 40 character wide limit on the line we are poking onto, we also poke the same character vertically down the screen. 6 NEXT:A=161:B=241 The loop is repeated by the NEXT command. We then set the variable 'A' to 161, the colour attribute for character position 160. The variable 'B' is also set for attribute. We now have Poked a box of 40 characters wide and 23 characters deep with inverted spaces. 7 FOR J=1 TO 81 STEP 2 Now what is needed, is to get the box to flash colours onto the screen around that predefined box. We set a loop to execute the colour attribute of each character within that box, stepping twice. 8 IF AA<>48 THEN S=RND(1)*15:GOTO 11 If we have a colour screen then we want to Randomise 15 whole numbers to get colours. As it is colour, we avoid the next two lines. These are for mono. 9 S=RND(1)*2:IF S=1 THEN S=0 We Randomise 2 whole numbers. If S=1 the we want the colour BLACK. 10 IF S=2 THEN S=7 The variable is set to WHITE if not BLACK 旼컴컴� � 209 � 읕컴컴� 11 POKE J.S:POKE 3840+J,S We poke the attribute colour onto the screen, both top and bottom of the box. 12 POKE A,S:POKE B,S:A=A+160:B=B+160 We also poke the colour attributes down both the sides of the box. 'A' is increased by one line as is 'B'. 14 IF B>=3920 THEN A=161:B=241 If 'B' is greater than or equals to 3920 the 'A' is made to ODD numbers, so to is the variable 'B'. This is for the colour attribute of the current character. 15 NEXT:GOTO 7 Once the loop has been completed, we go over the same ground to give us a great screen display. 旼컴컴� � 210 � 읕컴컴� Dis/Enable Keyboard 컴컴컴컴컴컴컴컴컴� Disable keyboard (while doing a special process) DEF SEG=64:OUT 97,204 then Enable again with DEF SEG=64:OUT 97, 76 Check for various devices 컴컴컴컴컴컴컴컴컴컴컴컴� 6000 DEFINT A-Z:DEF SEG=&H40:KEY OFF:F$=" no" 6001 MEMORY=PEEK(&H13)+PEEK(&H14)*256 6002 DISKS=(PEEK(&H10) AND &HC0)\&H40+1 6003 HARD=PEEK(&H75) 6004 PRINTERS=(PEEK(&H11)AND &HC0)\&H40 6005 SERIAL=(PEEK(&H11)AND &HE)\2 6006 GAMEPORT=(PEEK(&H11)AND &H10)\&H10 6007 IF(PEEK(&H10)AND &H30)=&H30 THEN MONO=-1 6008 DEF FNNUM$(X)=MID$(F$+STR$(X),-3*(X<>0)+1,4) 6009 CLS:COLOR 7,0 6010 PRINT "Floppy Drives: ";FNNUM$(DISKS) 6011 IF HARD THEN PRINT "Hard Drives: ";FNNUM$(HARD) ELSE PRINT "No Hard Drives" 6012 IF PRINTERS THEN PRINT "Printer Ports: "; FNNUM$(PRINTERS) ELSE PRINT"No Printer Ports": IF SERIAL THEN PRINT "You may have a Serial Printer" 旼컴컴� � 211 � 읕컴컴� 6013 IF SERIAL THEN PRINT "Serial Ports: "; FNNUM$(SERIAL) ELSE PRINT "No serial Port" 6014 IF GAMEPORT THEN PRINT "A Games Port" ELSE PRINT "No Games Port" 6015 IF MONO THEN PRINT "Monochrome ;"; ELSE PRINT "Color/Graphics "; 6016 PRINT"Screen adaptor" 6017 COLOR 7,0:DEF SEG:END 旼컴컴� � 212 � 읕컴컴� USING THE COMMAND$ STRING FOR QUICK BASIC COMPILERS 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� You can have a system, whereby the USER can make some selections from the DOS command line. This term is called SWITCHES. You see them quite often. You are normally given options to load a program in. ie; TEST /N/V and so on. 1 CLS:CLINE$=COMMAND$:TLENGTH=LEN(COMMAND$) Clear the screen. Look at the COMMAND$ line and set the TotalLENGTH variable to its total length. 2 MAXIMUN=(TLENGTH/2)+1 What we want is to be able to Dimension a string variable later on with the total switche commands used. 3 DIM ARG$(MAXIMUM) We now dimesion the ARG$ (argrement) string to the total of commands on the COMMAND line. 4 TRUE=-1:FALSE=0:I=1:NUMBER=0:INWORDS=TRUE We now set up some variables to control the flow of the program 5 WHILE I<=TLENGTH Using the WHILE/WEND commands, we state that, WHILE the variable 'I' is less than or equals to the TotalLength, we do the following: 6 CH$=MID$(CLINE$,I,1) String CH$ will be equals to MID$ of the COMMAND line for each single character as long as: 旼컴컴� � 213 � 읕컴컴� 7 IF CH$<>" " THEN If our CH$ (Character Buildup String) is not equals to a SPACE, we do the following: 8 IF NOT INWORDS THEN INWORDS=TRUE 9 ARG$(NUMBER)=ARG$(NUMBER)+CH$ The dimensioned array string is built up for each character that does not have a space after it. Otherwise; 10 ELSE IF INWORDS THEN assuming that the variable INWORDS is true, we can; 11 NUMBER=NUMBER+1 increase the numbers of our ARGument$. 12 INWORDS=FALSE We know that a complete Switch command has been made, so we set out control variable to FALSE to tell us that we are ready for another. 14 END IF We now END the multiple IF commands. 15 I=I+1 We increment the variable 'I' by 1, so that the WHILE command on line 5 will know what it is soposed to do. 16 WEND We must use this command when using the WHILE command. 旼컴컴� � 214 � 읕컴컴� If you want to see what SWITCHES were used, add the following: 17 FOR i=0 to number:print arg$(i):next 旼컴컴� � 216 � 읕컴컴� ALPHABETICAL INDEX 컴컴컴컴컴컴컴컴컴 Append 50 Command structures 147 Command Line Switches (Compilers) 95,212 Data handling 150 Dis/Enable Keyboard 210 DOS keyboard fonts 206 Editing keys 130 Error messages 196 Error trapping 142 File handling 132 Function keys 33 FUNKEY1.BAS 33 FUNKEY2.BAS 35 Getting input from the keyboard 173 Graphics 163 I/O communications 192 INDELOT.BAS 13 Introduction 2 Let's Get Going 10 旼컴컴� � 217 � 읕컴컴� LOADER.BAS 21 Machine code 185 Manipulating Strings 10 Mathematics 153 Memory (RAM) 206 Memory accessing 189,206 Monitor type 206 ON ERROR and RESUME 49 Peek and Poke Grey keys 30 PK-BRD.BAS 30 Printer output 179-180 PRINTER.BAS 38 Read and Data commands 24 Reading and Saving data files 47 Screen locations 207-209 Screen output 156 Shortcut keys for the editor 129 Similar dos type commands in basic 127 Sound commands 187 Special keys 205 String handling 175 旼컴컴� � 218 � 읕컴컴� STRINGS.BAS 10 Techniques in using the interrupts 181 The direct command from DOS 118 The editor and its commands 120 TXT2COM.BAS 25 USEFUL TIPS 205 Using the printer 38 Variables and constants 144 WRAP1.BAS 52 旼컴컴� � 220 � 읕컴컴� FUNCTION INDEX 컴컴컴컴컴컴컴 * Multiplication 153 + Addition 153 + Concatention 153 - Subtraction 153 / Division 153 < Less than 150 <= Less than or Equal to 150 <> Not equal to 150 = Equal to 150 > Greater than 150 >= Greater than or Equal to 150 ^ Exponentiation 153 ABS 153 AND 150,153 Arrays 144-146 deleting 144 dimensioning 144 ASC 151 ASCII characters 151 ATN 153 AUTO 120 BASIC 118 BASICA 118 BEEP 187 Binary files 189 BLOAD 189 BSAVE 189 CALL 185 CALL$ 185 CDBL 151 CHAIN 132 CHDIR 127 CHR$ 151 CINT 151 CIRCLE 163 CLEAR 120 Clearing Memory 124 CLOSE 132-133 旼컴컴� � 221 � CLS 156 읕컴컴� COLOR 156-157,163-166 COMMON 133 Communications 62,192 buffer data (receive) 192 buffer data (send) 194 buffer functions 192 delay for port change 194 line length (COM) 193 opening channels 193-195 port value 192 writing to a port 194 Concatenation 175 Constants 144-146 CONT 120 Convensions 151 ASCII/decimal 151 decimal/ASCII 151 decimal/hex 152 decimal/octal 151 double-precision 151 number/string 151 single-precision 151 string/number 152 COS 153 CSNG 151 CSRLIN 157 Cursor::: column 157-158 location 158 position 158 CVD 133 CVI 133 CVS 133 Data::: comparisions 150-152 conversion 151-152 pointer 144 tables 144 DATE$ 175 DEF FN 151,175 旼컴컴� � 222 � 읕컴컴� DEF SEG 189,206 DEF USR 185 DEFDBL 144 DEFINT 144 DEFSGN 144 DEFSTR 144 DELETE 120 Deleting lines 120 DIM 144 Directory 127 change 127 creation 127 removal 127 Double-precision 151 DRAW 164 EDIT 121 Editing commands 121 auto-line numbers 120 renumber lines 124 ENVIRON 127 EVIRON$ 127 EOF 133 EQV 154 ERASE 144 ERDEV 142 ERDEV$ 142 ERL 142 ERR 142 ERROR 142 Error::: codes 142,196 device 142 generation 142 handling 142 numbers 142,196 trapping 142,142,196 Execution line number 120 program 124-125 Exiting GW-/BASIC 126 EXP 154 旼컴컴� � 223 � 읕컴컴� FIELD 134 FILES 121 append 50,137,138 closing 132 deleting 120 end-of- 133 formatting data 138 opening 137,138,180,192 position 134,136 random access 134,138,197 reading 134,145 renaming 132 size 138 writing 140,195 FIX 154 FN 151,175 FOR..NEXT 137,147 FRE("") 121 FRE(0) 121 Free memory 121 Function keys 121 Garbage collection 133,135,121 GET 134,166,192 GET# 134,192 Global data 144 GOSUB...RETURN 148 GOTO 121,148 Graphics::: circles 163 clearing points 169 coordinates 168 displaying 164 drawing 164-166 ellipses 163 graphic colours 163-164 lines 164-166,167 painting 168 point colour 169 rectangles 164-166 screen mode 168 setting points 169 旼컴컴� � 224 � 읕컴컴� storage 166 windows 172 BASIC/A/GW 118 Hardcopy 152 HEX$ 152 IF..THEN..ELSE 148 IMP 154 INKEY$ 173 INP 192 INPUT 173 INPUT# 134,135 INPUT$ 134-135,173 INSTR 176 INT 154 Integers 150 Interupts 181-184 communications 182 key definition 181 key reading 134,182 PLAY buffer 183 timer reading 112,128,184 IOCTL 128 IOCTL$ 128 Jumps::: conditional 121 unconditional 148 KEY 121-122 Keyboard input::: line programming 173 prompting 173 reading ASCII values 173-174 reading characters 145,173-174 KEY LIST 121-122 KEY OFF 121 KEY ON 121 KILL 135 LCOPY 179 LEFT$ 176 LEN 138,176 LET 144-145 LINE 135,167,173 旼컴컴� � 225 � 읕컴컴� LINE INPUT 135 LINE INPUT# 75,135 Line width 192 LIST 121-123 LLIST 122-123 LOAD 123 LOC 135,192 LOCATE 157-158 LOF 135,192 LOG 154 LPOS 179 LPRINT 179-180 LPRINT USING 180 LSET 136 Machine language::: calling 185 user-defined 185 Mathematics::: absolute values 153 addition + 153 arctangent ATN 153 cosine COS 153 division \ or / 153 equivalence EQU 154 exclusive or OR 151 exponent EXP 154 exponentiation 153 implication IMP 154 integer part INT 154 logical and AND 153 logical not NOT 155 logical or XOR 155 modular division MOD 155 multiplication * 153 natural logarithmn LOG 154 sign SGN 155 sine of angle SIN 155 square root SQR 155 subtraction - 153 tangent of angle TAN 155 truncation FIX 154 旼컴컴� � 226 � 읕컴컴� Memory access 189-191 binary data loading 189 binary data saving 189 read memory 24,45,190,196 segment addresses 190 variable pointers 191 write to memory 190 MERGE (Merging programs) 124 MID$ 177-178 MKDIR 127 MKD$ 136 MKI$ 136 MKS$ 136 MOD 155 MS-DOS 127 drivers 128 environment table 127 programs 129 Music programming [Sound] 187-188 NAME 137 NEW 124 NOT 51,155 OCT$ 152 ON COM 182 ON ERROR GOTO 49,142 ON KEY 182-183 ON PLAY 182-183 ON TIMER 183 ON X GOTO 184 ON X GOSUB 184 OPEN 137,138,180,192-194 OPEN COM 192-194 OPTION BASE 145 OR 151 OUT 194 Overlays 132-139 PAINT 160 PEEK 190 PLAY 183 PMAP 168 POINT 169 旼컴컴� � 227 � 읕컴컴� POKE 190 POS 158 PRESET 169 PRINT 127,139,140,160 PRINT USING 160-162 PRINT# 140 PRINT# USING 140 Printer 179-180 buffer position 179 formatted data 180 line width 180 Program::: comment (REM,') 124 listing (printer) 122-123 listing (screen) 122 loops 147 PSET 169-170 PUT 179 PUT# 170,195 RANDOMIZE 154 Random numbers 154 READ 145 Reading memory 145 REM 124 RENUM 124 RESTORE 146 RESUME 49,143 RIGHT$ 177 RMDIR 127 RND 152 RSET 136 RUN 124-125 Running BASIC/A/GW 125 SAVE 125-126 SCREEN 158-159,171-172 Screen::: clearing 120 display 156 format 157-158 pages 156 Segment addresses 190-191 旼컴컴� � 228 � SGN 155 읕컴컴� SHELL 128 SIN 155 Single-precision 153 SOUND 188 SPACE$ 177 Spaces 162 SQR 155 Starting GW-/BASIC 124 STOP 126 STR$ 152 String::: concatenation 175 definition 175 dissection 176 functions 175 searching 176 STRING$ 178 Subroutines 148 SWAP 146 SYSTEM 126 System date 175 System time 175 TAN 155 TIME$ 175 TIMER 128,184 Tone production 187-188 Trace mode::: TROFF 126 TRON 126 User-defined functions 144,151-152,175 USR 185 VAL 152 Variable::: content exchange 146 initilization 144 pointers 189-191 VARPTR 190 VARPTR$ 189-190 VIEW 172 VIEW PRINT 159 旼컴컴� � 229 � 읕컴컴� WAIT 195 WHILE..WEND 149 WIDTH 180,195 WINDOW 159 WRITE 162 WRITE# 139 Writing to memory 190 XOR 155 旼컴컴� � 230 � 읕컴컴� How to protect your Copyright 컴컴컴컴컴컴컴컴컴컴컴컴컴컴� After you have completed the program with its documentation and listings, send [ via Registered Post ] the documentation and listing to yourself and [ optional ] to a solictor. Make sure the the package is never tampered with, or that could make things very differcult to prove Copyright ownership in a court of law. There again, if you have the orignal listings of code it could be enough. I suggest that you do not leave things to chance. Always place a full copyright notice within the first screen of the document file and [ if possible ] on the title page of the program. EXAMPLE: 컴컴컴컴 (C) Copyright Mr Book On Shelf. September 1987. All rights reserved. Place your name and FULL address, including Country. Add any conditions and restrictions for the use of the product or products. Always state that the product must stay complete with documentation and all files as distributed. State: no copying, Sale, Point of Sale, Distribution, Passing around and so on. Decide what is relevent for you. Although Copyright is De-facto in Great Britian, proving it is another matter. This is the reason as to why this information has been placed in this book. 旼컴컴� � 231 � 읕컴컴� ANSI Colour Graphics 컴컴컴컴컴컴컴컴컴컴 Using ALT/27 [ESC] and left open square bracket [. Foreground with Black Background 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 Black 0;30;40m Blue 0;34;40m Green 0;32;40m Cyan 0;35;40m Red 0;36;40m Purple 0;31;40m Yellow 0;33;40m White 0;37;40m Highlighted 컴컴컴컴컴� Blue 0;1;34;40m Green 0;1;32;40m Cyan 0;1;36;40m Red 0;1;31;40m Purple 0;1;35;40m Yellow 0;1;33;40m White 0;1;37;40m Foreground Normal Flashing [47 is black background] 컴컴컴컴컴컴컴컴컴컴컴컴컴 Black 0;5;30;47 Where 30 is, it is Foreground colour. Where 47 is, it is Background colour Blue 34 Green 32 Cyan 33 Red 36 Purple 31 Yellow 33 White 37 Foreground Flashing Highlighted, 47= Black background 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� Gray 0;1;5;30;47 Where 30 is, it is foreground colour. Where 47 is, it is background colour. Blue 34 Green 32 Cyan 36 Red 31 Purple 35 Yellow 33 White 37 Background Colours 컴컴컴컴컴컴컴컴컴 Black=40 Blue=44 Green=42 Cyan=46 Red=41 Purple=45 Yellow 43 White 47 When printing a combintion of characters, place a small 'm' infront the very first character. If placing the cursor command just before the printed character, don't use 'm'. If you require to alter 旼컴컴� � 232 � 읕컴컴� the colour after the printed character/s, then issue ALT/27 [ESC] plus open square bracket with any colour code sequence. EXAMPLE: ESC[0;37;40mThis is a testESC[0;33;40m Command ASCII Dos Colour 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� Clear Home ESC[2j Attributes OFF ESC[0m- Bold ON ESC[1m add 8 Underscore ON IBM MONO ESC[4m Blink ON ESC[5m add 128 Reverse ON ESC[7m Visable Cancel ON ESC[8m Foreground 컴컴컴컴컴 Black ESC[30m 0 Red ESC[31m 4 [12=Bold] Green ESC[32m 2 [10=Bold] Yellow ESC[33m 6 [14=Bold] Blue ESC[34m 1 [9 =Bold] Purple ESC[35m 5 [13=Bold] Cyan ESC[36m 3 [11=Bold] White ESC[37m 7 [15=Bold] Background 컴컴컴컴컴 Black ESC[40m Red ESC[41m Green ESC[42m Yellow ESC[43m Blue ESC[44m Purple ESC[45m Cyan ESC[46m White ESC[47m 旼컴컴� � 233 � 읕컴컴� Cursor Movement 컴컴컴컴컴컴컴� Cursor Right\left ESC[1 to 79 C Cursor Down\up ESC[1 to 22 H Cursor Home [top left] ESC[H Clear Screen and Cursor Home ESC[2j Cursor UP one ESC[u 旼컴컴� � 234 � 읕컴컴� ASCII CODES 컴컴컴컴컴� DEC HEX CHAR NAME Controle Codes 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 0 0 CTRL-@ NUL NUL 1 1 CTRL-A SOH Start of Heading 2 2 CTRL-B STX Start of Text 3 3 CTRL-C ETX End of Text 4 4 CTRL-D EOT End of transmit 5 5 CTRL-E ENQ Enquiry 6 6 CTRL-F ACK Acknowledge 7 7 CTRL-G Bel Bell 8 8 CTRL-H BS Back Space 9 9 CTRL-I HT Horizontal Tab 10 A CTRL-J LF Line Feed 11 B CTRL-K VT Vertical Tab 12 C CTRL-L FF Form Feed 13 D CTRL-M CR Carriage Return 14 E CTRL-N SO Shift Out 15 F CTRL-O SI Shift IN 16 10 CTRL-P DLE Data Line Escape 17 11 CTRL-Q DC1 Device Control 1 18 12 CTRL-R DC2 Device Control 2 19 13 CTRL-S DC3 Device Control 3 20 14 CTRL-T DC4 Device Control 4 21 15 CTRL-U NAK Negative Acknowledge 22 16 CTRL-V SYN Synchronous Idle 23 17 CTRL-W ETB End of Transmit Block 24 18 CTRL-X CAN Cancel 25 19 CTRL-Y EM End of Medium 26 1A CTRL-Z SUB Subsitute 27 1B CTRL-[ ESC Escape 28 1C CTRL-\ FS File Separator 29 1D CTRL-] GS Group Separator 30 1E CTRL-^ RS Record Separator 31 1F CTRL-� US Unit Separator 旼컴컴� � 235 � 읕컴컴� DEC HEX CHAR DEC HEX CHAR 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 32 20 71 47 G 33 21 ! 72 48 H 34 22 " 73 49 I 35 23 # 74 4A J 36 24 $ 75 4B K 37 25 % 76 4C L 38 26 & 77 4D N 39 27 ' 78 4E M 40 28 ( 79 4F O 41 29 ) 80 50 P 42 2A * 81 51 Q 43 2B + 82 52 R 44 2C , 83 53 S 45 2D - 84 54 T 46 2E . 85 55 U 47 2F / 86 56 V 48 30 0 87 57 W 49 31 1 88 58 X 50 32 2 89 59 Y 51 33 3 90 5A Z 52 34 4 91 5B [ 53 35 5 92 5C \ 54 36 6 93 5D ] 55 37 7 94 5E ^ 56 38 8 95 5F _ 57 39 9 96 60 ` 58 3A : 97 61 a 59 3B ; 98 62 b 60 3C < 99 63 c 61 3D = 100 64 d 62 3E > 101 65 e 63 3F ? 102 66 f 64 40 @ 103 67 g 65 41 A 104 68 h 66 42 B 105 69 i 67 43 C 106 6A j 68 44 D 107 6B k 69 45 E 108 6C l 70 46 F 109 6D m 旼컴컴� � 236 � 읕컴컴� DEC HEX CHAR DEC HEX CHAR 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 110 6E n 149 95 _ 111 6F o 150 96 � 112 70 p 151 97 � 113 71 q 152 98 � 114 72 r 153 99 � 115 73 s 154 9A � 116 74 t 155 9B � 117 75 u 156 9C � 118 76 v 157 9D � 119 77 w 158 9E � 120 78 x 159 AF � 121 79 y 160 A0 � 122 7A z 161 A1 � 123 7B ( 162 A2 � 124 7C : 163 A3 � 125 7D } 164 A4 � 126 7E ~ 165 A5 � 127 7F 166 A6 � 128 80 � 167 A7 � 129 81 � 168 A8 � 130 82 � 169 A9 � 131 83 � 170 AA � 132 84 � 171 AB � 133 85 � 172 AC � 134 86 � 173 AD � 135 87 � 174 AE � 136 88 � 175 AF � 137 89 � 176 B0 � 138 8A � 177 B1 � 139 8B � 178 B2 � 140 8C � 179 B3 � 141 8D � 180 B4 � 142 8E � 181 B5 � 143 8F � 182 B6 � 144 90 � 183 B7 � 145 91 � 184 B8 � 146 92 � 185 B9 � 147 93 � 186 BA � 148 94 � 187 BB � 旼컴컴� Continued .... � 237 � 읕컴컴� DEC HEX CHAR DEC HEX CHAR 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 188 BC � 222 DE � 189 BD � 223 DF � 190 BE � 224 E0 � 191 BF � 225 E1 � 192 C0 � 226 E2 � 193 C1 � 227 E3 � 194 C2 � 228 E4 � 195 C3 � 229 E5 � 196 C4 � 230 E6 � 197 C5 � 231 E7 � 198 C6 � 232 E8 � 199 C7 � 233 E9 � 200 C8 � 234 EA � 201 C9 � 235 EB � 202 CA � 236 EC � 203 CB � 237 ED � 204 CC � 238 EE � 205 CD � 239 EF � 206 CE � 240 F0 � 207 CF � 241 F1 � 208 D0 � 242 F2 � 209 D1 � 243 F3 � 210 D2 � 244 F4 � 211 D3 � 245 F5 � 212 D4 � 246 F6 � 213 D5 � 247 F7 � 214 D6 � 248 F8 � 215 D7 � 249 F9 � 216 D8 � 250 FA � 217 D9 � 251 FB � 218 DA � 252 FC � 219 DB � 253 FD � 220 DC � 254 FE � 221 DD � 255 FF 旼컴컴� � 238 � 읕컴컴� EXTENDED Key Codes 컴컴컴컴컴컴컴컴컴 SHIFT and Dec Hex CTRL and Dec Hex 컴컴컴컴컴컴컴컴컴컴컴 컴컴컴컴컴컴컴컴컴컴 F1 84 54 F1 94 5E F2 85 55 F2 95 5F F3 86 56 F3 96 60 F4 87 57 F4 97 61 F5 88 58 F5 98 62 F6 89 59 F6 99 63 F7 90 5A F7 100 64 F8 91 5B F8 101 65 F9 92 5C F9 102 66 F10 93 5D F10 103 67 ALT and Dec Hex F keys ONLY.Dec Hex 컴컴컴컴컴컴컴컴컴컴컴 컴컴컴컴컴컴컴컴컴컴� F1 104 68 F1 59 3B F2 105 69 F2 60 3C F3 106 6A F3 61 3D F4 107 6B F4 62 3E F5 108 6C F5 63 3F F6 109 6D F6 64 40 F7 110 6E F7 65 41 F8 111 6F F8 66 42 F9 112 70 F9 67 43 F10 113 71 F10 68 44 CTRL and Dec Hex ALT and Dec Hex 컴컴컴컴컴컴컴컴컴컴� 컴컴컴컴컴컴컴컴컴컴 A 1 1 A 30 1E B 2 2 B 48 30 C 3 3 C 46 2E D 4 4 D 32 20 E 5 5 E 18 12 F 6 6 F 33 21 G 7 7 G 34 22 H 8 8 H 35 23 I 9 9 I 23 17 J 10 A J 36 24 旼컴컴� Continued .... � 239 � 읕컴컴� CTRL and Dec Hex Alt and Dec Hex 컴컴컴컴컴컴컴컴컴컴� 컴컴컴컴컴컴컴컴컴컴 K 11 B K 37 25 L 12 C L 38 26 M 13 D M 50 32 N 14 E N 49 31 O 15 F O 24 18 P 16 10 P 25 19 Q 17 11 Q 16 10 R 18 12 R 19 13 S 19 13 S 31 1F T 20 14 T 20 14 U 21 15 U 22 16 V 22 16 V 47 2F W 23 17 W 17 11 X 24 18 X 45 2D Y 25 19 Y 21 15 Z 25 1A Z 44 2C Standard keys: Special Keys. 컴컴컴컴컴컴컴 컴컴컴컴컴컴� Key Dec Hex DEFSEG=64 컴컴컴컴컴컴컴컴컴� A=PEEK(64) Home 71 47 DEF SEG=0 End 79 4F A= VALUE OF KEY PgUp 73 49 OFF ON Hex PgDn 81 51 CTRL LOCK 0 64 40 Ins 82 52 NUM LOCK 0 32 20 .Del 83 53 SCROLL LOCK 0 16 10 <-Del 8 8 INS 0 128 80 Tab > 9 9 CTRL 0 4 4 Tab < 15 F ALT 0 8 8 Cur Up 72 48 LEFT SHIFT 0 2 2 Cur Dn 80 50 RIGHT SHIFT 0 1 1 Cur Lft 75 4B Cur Rgt 77 4D Variable A contains value.