VP/ix defined COM1 causes immediate CORE DUMP. Why?

[Bill Irwin]

[Followups to comp.unix.msdos]

I have just hit a MAJOR problem with VP/ix running on SCO XENIX
2.3.3.  I have an application that needs to use a modem, so I
mapped (in vpix.cnf) COM1 to /dev/ttya7.  The modem is connected
to a Texas Instruments CB811 8 port mux (which doesn't support
modem control 8^( ).

As soon as VP/ix is run with COM1 defined, the system crashes
with an entry in /etc/messages about an unrecoverable kernel page
fault.  This also happens when I define COM2.

The VP/ix manual says that you cannot have COM1 defined to a
Xenix device that is also a serial terminal.  So I thought of
disabling the modem port before invoking VP/ix.  No luck..it
still crashed.

I suspect that this may be a problem with the CB811 mux, which I
believe is a Computone that is OEMed by TI.  Has anyone had any
experience like this and solved it?  Thanks for any help you can
offer.
-- 
Bill Irwin    -       The Westrheim Group     -    Vancouver, BC, Canada
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