Using COM3 under SCO XENIX

[SPIESMAN, BILL]

I have added a mouse to my i386 XENIX system. I put it on
the COM2 serial port. I find that my I/O board cannot
be configured for COM1 and COM2 use; only a COM2/COM3
or COM1/COM4 combination. Thus I must add a new device
to my system (COM3 = tty3a = tty3A). Has anybody had
any experience with this? I tried a variety of things:
mkdev, mknod+manual editting of /etv/ttys and /etc/ttytype,
but I cannot get this new device to function. All that
happens is that a new tty3a,tty3A device shows up in the
/dev directory, but when I try to use it (cu or kermit) I
get a 'no such device/address' message.

I might add that the COM2/COM3 combination works fine
when I boot up DOS, so the problem is in software and
not hardware.
Any hints? Thanks in advance.

Bill Spiesman
spiesman at amarna.gsfc.nasa.gov