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HW: Thinkpad 755CD, 800MB disk, 24MB memory.
IBM patches installed: uttpg101/102, sytpe144, mwmidiw1, mw95225x.
OS: Win95 4.00.950 B.
Problem: The serial port works only one way with kermit. If I run
kermit on the laptop, and connect the serial port to something
else, then chars that I type on the laptop appear on the other
end. However, chars that I type on the other end don't appear on
the laptop.
The other end is either a dumb tty or a workstation running
kermit. I've tested every component of the cable to the laptop by
connecting another connector to it, then using that to connect the
tty and the workstation. Chars flow both ways.
The laptop's bios self test passes the serial port.
Where should I look now? Altho it could theoretically be a broken
wire on the internal side of the port connector, I'm leaning
towards a SW problem, perhaps a modem config problem, even tho
there is no modem in use. Kermit says that CD, DSR, and CTS are
all off, which is very suspicious.
Is there any way to config the serial port to pretend that all
these modem signals are on? I've browsed all the obvious places
on the laptop.
I also tried hyperterm in place of kermit on the laptop. It also
works unidirectionally, except that it tends to lock up so badly
that c-a-del scarcely works.
Serial port A is COM1, using IRQ 4. Nothing else is
using IRQ 4 (since I disabled the IR). The serial port has
power.
Thanks for any help.
------------------------
Wm. Randolph Franklin
Associate Professor
wrf@ecse.rpi.edu
http://www.ecse.rpi.edu/Homepages/wrf/
+1 (518) 276-6077; Fax: -6261
ECSE Dept., 6026 JEC, Rensselaer Polytechnic Inst, Troy NY, 12180 USA
(PGP key available)