kermit.Configuring Linux to use the Mac as a login: terminal is even
easier. kermit is ideal for this purpose, because it is one
of the few free communication programs which provides credible
VT100/120/220 emulation.
Essentially, what you want to do is start kermit on the
Macintosh side as in the previous section, but rather than issue
server commands, you enter connect mode. This is the normal
terminal emulation mode that most people use, anyway.
On the Linux side, the serial line must be configured with a
getty on it to start a login: shell. To do this,
you need to tell init that the serial line has a terminal on
it. In your /etc/inittab file you will need a line something
like this:
T1:23:respawn:/sbin/getty -L ttyS0 9600 vt100Be sure to substitute the appropriate serial device for
/dev/ttyS0 and the correct baud rate for 9600 in the
command line above.
This command tells getty to start login (the
-L switch) on the terminal display, and, when the login times
out, to re-start (respawn) the login program until someone
logs in. If no device is connected to the serial line, or if the
connection is defective, you may see a message on the system console
like: /dev/ttyS0 respawning too fast: disabling for 5
minutes. If this happens, you can return things to normal by (as
root) killing the getty process, or using the
init q command. Both of them have the effect of re-spawning
the getty processe(s). If everything is in order, you should
see the Linux banner and login prompt on the Mac's kermit
window. That's all there is to it.
Also, if you use something besides vanilla getty, like
getty_ps, the command above will look somewhat different.
The important thing to remember is that everything to the right of
/sbin/getty is an argument for getty itself; not
init. You should look at the manual pages for
getty, init,and inittab if you have
questions concerning the setup of init and getty.
The Serial HOWTO provides helpful details on how to configure
/etc/inittab for getty_ps, if that's what your
system uses.
To transfer files back and forth between the Macintosh and the Linux
machine, you can (via the Mac's Kermit) issue the kermit -x
command to start the Linux kermit in server mode. You can
then use the normal file transfer commands to send files across
the serial line. It's useful to set a prompt in your
~/.kermrc with a line like
set prompt Linux-kermit >Otherwise, remembering which machine you're on can quickly become confusing.
This method should work equally well for any other Mac terminal
program. If you have ZTerm, you can use rz and sz
on the Linux machine to transfer files via the ZModem protocol. If
Microphone Lite came bundled with your fax modem, that works
equally well, albeit without kermit's superior scripting and
configuration facilities.