Configuring HP-UX For Peripherals

Chapter 4 133
Configuring Terminals and Modems
Troubleshooting Terminal Problems
— wires are partially shorted or broken within the cable.
— telephone connection is noisy
• Parity is incorrectly set. (See “Differences between Console and
Terminal Configuration”.)
• Hardware problem with a modem, interface card, or the terminal
itself
• The program performing I/O might be sending the garbage
• The Display Functns* feature of your terminal is enabled (which
displays characters that would not normally print)
• You might be displaying a non-ASCII file.
If everything printed is garbage, examine these possible causes:
• Baud-rate mismatch (most likely) If your terminal's speed setting
differs from that read by the stty command, garbage will appear on
your screen.
If you have not yet logged in, press the Break key, followed by Return,
Return, to force getty to try the next entry in /etc/gettydefs.
Typically, the gettydefs file is set up so that each time you press the
Break key, getty tries the next speed setting, as defined in
/etc/gettydefs. When getty matches the speed set to your
terminal, you will get a readable login prompt.
• Parity generation/checking mismatch. Use stty to determine the
proper settings for the terminal.
• The TERM environment variable is incorrectly set. If you have an HP
terminal, try setting the TERM value to hp using your shell's set
command.
• A running process is producing garbage output.
• The cable might be miswired or the data line might be noisy.
• You might have a hardware failure in your interface card, modem,
MUX or other device.
The TERM environment variable is required for software compatibility
with the terminal. At the time of login, HP-UX software reads the
terminfo setting. If you have changed the configuration during a
terminal session, you need to alert the software to the change by
exporting the TERM variable. For example, in Korn shell, export
TERM=vt100