duncan hall wrote:
>
> Thanks,
>
> Using a serial port would be fine.
>
> Unfortunately using a crossover cable and the network card is not possible.
>
> Can someone point me in the right direction for some documentation and or
> programmes?
You can read the Serial-HOWTO (should be on your Mandrake CD
if not already on your hard drive).
Basically, what you do is change one of the gettys in inittab
to reference an external dumb terminal via a serial port,
rather than reference one of the internal virtual consoles.
The virtual console is what you have now: a keyboard and
monitor, which you select with the ALT-Fx key (in console
mode, not in X windows).
When the computer boots, the sign-on messages default to VC#1.
There are several VC's, but #1 is the one that gets the
messages.
The lines in /etc/inittab that do this look like this:
1:12345:respawn:/sbin/mingetty tty1
2:12345:respawn:/sbin/mingetty tty2
etc
In the above lines, the first number is the Virtual console
number. The 12345 means that it works on those run levels.
tty1, tty2 is the virtual serial port. Mingetty is a
"minimal getty" that runs ONLY virtual consoles.
What you want to do is to use a full-fledged getty. The
HOWTO mentions several; the easies to use is uugetty which
needs very little work. I *believe* you will need a
/etc/getty.defs file, but it may not be neccessary. Try
this line in place of the console VC#2 line, and try to see
if you can work a dumb terminal attached to your serial
port cua0 (COM1). Change any port numbers as needed:
2:12345:respawn:/sbin/uugetty cua0 9600 vt100
that means that console #2 will output to the serial port at
9600 baud, and use vt100 emulation. This should work with
most dumb terminal emulation programs, such as Windows 95
Hyper Term (Hyperterm 3 and 4 are better than the one that comes
with Win95, but the built in one will work okay).
It is neccessary to either reboot or run this command in order
for the changes to /etc/inittab to become effective:
prompt# telinit q
You should also be aware that if you make any sort of error
in your /etc/inittab file, your system may not boot properly.
If you use an editor, make sure it does not wrap long lines
on your file. I use pico, but you have to use the -w (no wrap)
option, like this
prompt# pico -w inittab
failure to do so will give you lots of grief. vi is more
reliable in this regards, but harder to use.
At any rate, edit the file, attach a dumb terminal, reboot
or do the telinit q command and you should see a login
prompt on your dumb terminal. You may have to hit the enter
key a couple of times to wake it up; or you may have to change
the dumb terminal settings from hardware (CTS/RTS) to software
(XON/XOFF) handshake. The line above set it to 9600. Some
serial ports have trouble operating above 4800. If you get
garbage characters or lost characters or errors, try different
handshaking and/or lower speeds. Conversely, you can crank
it up higher if you can get away with it. Windows 3.1 generally
will need 1,200 baud, but Windows 95 can often get to
19,200 or even higher. Real old laptops, even the 286 variety,
work okay for this purpose.
Once you have it all debugged and working properly on the
second console port, you can re-edit your inittab file so the
#1 console is the one on the serial port. You will then see
on the dumb terminal all the Linux sign-on messages etc when
you reboot linux.
There are man pages on uugetty, as well as the mentioned
HOWTO. Read them for details. Be aware that some gettys are
hard to get going; I think that uugetty will be the easiest
and your best bet.
If you have a real dumb terminal, such as a wyse-50, or ADM-3
you can change the vt100 to that type. Look up the exact
spelling of the terminal name in /etc/termcap. With your
laptop, using either Win95 or Linux, the vt100 should be fine.
You will find that Windows 95 Hyperterm is not the best of
programs....there are some glitches and artifices in it. HTPE-3
from Hillgraeve is better; however if your laptop does Linux,
then using something like Minicom or some other terminal
program will yield far better results. But the Win95
program is useable as is and will certainly get you going
quicker as it needs no debugging.
The serial cable assembly should have all the wires if your
are going to do hardware handshake. You may have to play with
some serial port configuration using the setserial program;
however, if you use the full 9-wire cable you should have
no problems and any changes can be done in the laptop (hyperterm).
If you want to use a 3-wire cable, then setserial will probably
be neccessary. I use the full 9-wire cable here and have had
no problems using RTS/CTS hardware handshake.
Look at /var/log/messages from time to time. If you get
a message that says something like
tty1 respawning too fast, disable for 5 minutes
then there is something not working correctly, usually because
uugetty is not reading a needed configuration file, or there is
something wrong with the serial port. You need to understand
taht the getty programs 'respawn', that is, they start listening
on the port (or the virtual console). If something prevents
that from happening, the program restarts (respawns) every few
seconds. After beacoup attempts, it will give up for 5 minutes
then try again. So if you get this message, then its not working
and it will probably not work 5 minutes later. Go ahead and
change your setup and try again with telinit q and see what
happens.
Gettys are a lot of fun....specially getting them up and running
on a modem. But for a local terminal, they are easy to do.
Good luck!
--
Ramon Gandia ================= Sysadmin ================ Nook Net
http://www.nook.net [EMAIL PROTECTED]
285 West First Avenue tel. 907-443-7575
P.O. Box 970 fax. 907-443-2487
Nome, Alaska 99762-0970 ========== Alaska Toll Free. 888-443-7525
