[comp.sys.ibm.pc.hardware] Setting up OLD serial ports

BP3@psuvm.psu.edu (Larry Belan) (07/14/90)

Can someone explain to me why the old IBM serial ports
won't work as COM2?

I've got two of them and they both work if they are setup as com1
and the other is not in the machine.  But after flipping the
selection jumpers to set it as com2, it refuses to work...period.

I don't have the documentation for them, but since the jumpers are
so simple to switch, a two year old should be able to set it up
correctly (or am I overlooking something??)

If you have been able to get a similar set working, please E-Mail
me (don't post it to the net, there's enough traffic there.)

Larry Belan   (bp3@psuvm.psu.edu)  (412) 430-4163
PennState - Fayette Campus
Computer Center

davidsen@antarctica.crd.GE.COM (william E Davidsen) (07/18/90)

In article <90194.165250BP3@psuvm.psu.edu>, BP3@psuvm.psu.edu (Larry
Belan) writes:

|> I've got two of them and they both work if they are setup as com1
|> and the other is not in the machine.  But after flipping the
|> selection jumpers to set it as com2, it refuses to work...period.

  The fact that you say "jumpers" leads me to suspect that I know the
problem. There are two jumpers: the one in the top right hand corner is
the COM1/COM2 jumper. The other one changes from RS232 to 20ma current
loop. I doubt that you are running a tty33 in current loop mode, so if
you're changing that jumper you now know what your problem is.

  This information is in the manual.