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Installing an ASCII Terminal

This section describes the procedures for connecting and configuring an ASCII terminal. (Refer to the Serial Device Manager in your System Manager to accomplish many of the same tasks described in this section if you prefer to use a GUI to a command-line interface.)

The diagnostics terminal, or console, is the ASCII terminal connected to a serial port on the I/O panel of a server. It can be connected to any of these ports, depending on your system:

The messages produced by the power-on diagnostics appear on the screen of this terminal.

Configuring the Terminal Software

This section tells you how to configure IRIX software to use an ASCII terminal with your computer system.

During configuration, you need to

Note: The utilities described in this section are distributed as part of the eoe.sw.terminfo package. You must have installed this package on your system in order to use these utilities. See IRIX Admin: Software Installation and Licensing for information and specific instructions on installing this package.

The /usr/lib/terminfo directory contains files that describe different terminal models, their capabilities, and how they operate. For most ASCII terminal models, you do not need to edit this database.

Note: If your terminal is not in the database, or if it does not work properly after you have configured the software, you may need to write a terminal description. Refer to the optional Topics in IRIX Programming and the tset(1), stty(1), and terminfo(4) reference pages. Additionally, your terminal may support a compatible terminal mode (such as VT100). Check your terminal documentation for compatibility modes.

The directory /usr/lib/terminfo is divided into numeric and alphabetic subdirectories. Each subdirectory contains entries for terminals whose names begin with that character. For example, /usr/lib/terminfo/v contains the entry for the Visual 50. The entry name listed in the subdirectory is v50am.

To find the entry name for your terminal and to configure software for an ASCII terminal, follow these steps:

  1. Log in as root or become the superuser by entering the su command.

  2. To change directories to /usr/lib/terminfo, type

    cd /usr/lib/terminfo

  3. Find the entry name for your terminal. Issue the fgrep command with a string that you suspect could make up part of your terminal name.

    ls -R | fgrep -i string

    If this fails, examine the subdirectories of /usr/lib/terminfo, which contain all the terminal entries.

  4. Once you find the terminal name as it appears in /usr/lib/terminfo, issue the infocmp command to determine the model name of your terminal. For example, for a Visual 50, issue this command:

    infocmp -I v50am

    You will see a display that begins with this line:

    v50am|visual50 (v50 emulation) with automatic margins,

    The data in the first field (v50am) is the model name of your terminal.

    Note: If it looks as if there are many terminal names that could apply, use this sample shell script to help speed up the search. This example uses the string wy60* to help locate all the Wyse60 models. Substitute your own string, as appropriate.

    sh

    for i in wy60*

    do

    infocmp -I $i

    done

    If you choose an incorrect model name, you can change it later; the line still works, but screen-based commands do not display correctly.

  5. Edit /etc/ttytype and enter the model name.

    This file associates the model name with the port where the terminal is connected. In the line that contains the port you are using, replace v50am with the model name of your terminal.

    An /etc/ttytype might look like this example:

    iris-ansi systty
    ?v50am ttyd1
    ?v50am ttyd2
    ?v50am ttyd3
    ?v50am ttyd4
    ?v50am ttyd5
    ?v50am ttyd6
    ?v50am ttyd7
    ?v50am ttyd8
    ?v50am ttyd9
    ?v50am ttyd10
    ?v50am ttyd11
    ?v50am ttyd12

    The optional question mark (?) at the beginning of a line in /etc/ttytype causes tset to display the model name as supplied (for example, v50am here) and prompts for the model name you are currently using. If you are not using the model name as provided, type in the name that you are using; otherwise, press <Enter> to accept the default. This provides an easy way to switch terminal settings if you use more than one type of terminal.

    tset is normally called in your login startup script (.login or .profile). tset commands use information from /etc/ttytype and /usr/lib/terminfo to initialize the terminal. These files also provide information on setting environment variables so that editors and other programs know how to communicate with the terminal. See tset(1) for detailed information.

  6. Edit /etc/inittab so that you can log in. /etc/inittab provides information about how the computer ports behave. This sample is from an /etc/inittab file:

    t1:23:respawn:/etc/getty -s console ttyd1 co_9600 # port 1

    t2:23:off:/etc/getty -N ttyd2 co_9600 # port 2

    t3:23:off:/etc/getty -N ttyd3 co_9600 # port 3

    t4:23:off:/etc/getty -N ttyd4 co_9600 # port 4

    Here are two sample entries, with an explanation of each field in the entries:

    t1:23:respawn:/etc/getty -s console ttyd1 co_9600

    t2:23:off:/etc/getty -N ttyd2 co_9600

    t1 t2
    uniquely identifies the entry.

    23
    defines the init run level in which this entry is to be processed. A 23 means this entry is to be processed in run levels two and three. Refer to init(1M) for more information about run levels.

    off
    means do not perform the action on the process field of init.

    respawn
    means start the program in the process field of init and restart it every time the process terminates. See inittab(4) for a description of all possible actions.

    /etc/getty -s console ttyd1 co_9600

    runs the getty process on the port labeled 1 at the baud rate and with the options specified in the co_9600 entry in the /etc/gettydefs file. The -s console option instructs getty that the login shell generated is a system console and therefore receives system error messages.

    /etc/getty -N ttyd2 co_9600

    runs the getty process on the port labeled 2 at the baud rate and with the options specified in the co_9600 entry in the /etc/gettydefs file. The -N option instructs getty to honor the presence of the /etc/nologin file, which does not allow remote logins over the network.

    #
    text following this symbol is a comment to the end of line.

    To enable you to log in to the terminal connected to the port labeled 2, find this line:

    t2:23:off:/etc/getty -N ttyd2 co_9600

    Change it to

    t2:23:respawn:/etc/getty -N ttyd2 co_9600

  7. If you do not plan to run the terminal at 9,600 baud, replace co_9600 in /etc/inittab with the correct entry name from /etc/gettydefs.

    /etc/inittab refers to /etc/gettydefs for information about the terminal line settings. In the example from /etc/inittab above, co_9600 refers to the name of an entry in /etc/gettydefs; it defines a 9,600 baud console setting.

    To see what entries are defined in /etc/gettydefs, examine the file or see "Checking Line Settings Using IRIX Shell Commands". To make a new entry, see "Creating and Testing Line Settings".

  8. Inform init of the change to /etc/inittab and start a getty process for the port:

    telinit q

  9. Power on the terminal. The workstation sends a login prompt to the terminal screen. Press <Enter> if the login prompt does not appear.

Note: If the default line speed set in /etc/inittab is incorrect, the prompt may be garbled or may not appear. Choose another line speed.

Setting Terminal Options

The TTY system described thus far establishes a basic style of communication between the user's terminal and the IRIX operating system. Once a user has successfully logged in, he or she may prefer terminal options other than the default set.

The stty command controls terminal options. Many users add an stty command to their .profile or .login file so that the options they want are automatically set as part of the login process. Here is an example of a simple stty command:

stty cr0 nl0 echoe -tabs erase '^H'

The options in the example and their meanings are

cr0 nl0

No delay for carriage return or newline. Delays are not used on a video display terminal but are necessary on some printing terminals to allow time for the mechanical parts of the equipment to move.

echoe

Erases characters as you backspace.

-tabs

Expands tabs to spaces when printing.

erase '^H'

Changes the character-delete character to a ctrl-H. The default character-delete character is the pound sign (#). Most terminals transmit a ctrl-H when the <Backspace> key is pressed. Specifying this option makes <Backspace> delete the character that was just typed.

Refer to the stty(1) reference page for a full list of stty options.


Configuring the Terminal Software
Setting Terminal Options

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