Thinkpad and COM1 configuration
If you are going to use PPP via a Null Modem cable then you're going to
come up against problems with the Thinkpad.
It has two devices, an Infra-Red interface and COM1, that share the
same IRQ and IO address. By default IR is enabled and COM1 disabled.
Solaris does not have a configuration utility, so you need to run the
DOS version.
If you're lucky then you still have the Thinkpad documentation and
a DOS partition that contains the necessary stuff.
For the rest of us who are stuck with a machine that has neither (as
I was), here's what you do.
-
Download uttpfdos.exe from the IBM
web site. (ftp://ftp.pc.ibm.com/pub/pccbbs/mobiles/uttpfdos.exe)
-
Format a diskette and run uttpfdos.exe under DOS. It generates a bootable
diskette (disk A)
-
Format another diskette, including system files (disk B).
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Boot your Thinkpad using disk A.
-
Execute UINSTALL.EXE. When it asks you to insert the target diskette, put
in disk B. You'll need to ping-pong between disk A and disk B several times
as it asks for Source and Target disks. Don't give up! Keep on going!
-
When its all done, take disk B to a working DOS system and make a correction
to AUTOEXEC.BAT. The environment variable PS2MSG points to drive
C:. As you don't have a hard disk partition, change it to A:.
-
Boot your Thinkpad using disk B.
-
At the A> prompt do CD THINKPAD.
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For general help do PS2 ?.
-
To disable the IR port do PS2 IR DISABLE. Wait a couple of minutes until
you get the OK message and the A> prompt again.
-
To enable COM1 do PS2 SERA ENABLE. Wait a couple of minutes until you get
a message telling you to reboot the machine.
-
Take out the diskette and do the Vulcan salute (CTRL-ALT-DEL if you're
not a Trekkie).
-
You're done!
To check that COM1 is actually working, before you play with PPP, connect
the Thinkpad COM1 to a dumb terminal, or terminal emulator on another
machine. As root, copy a text file to /dev/cua0 e.g.
cat /etc/hosts > /dev/cua0.
You should see the text appear on the screen.
Please mail me if you run
into problems.
David Henry henryd@netvision.net.il