Problem with 3C503 card with ISC Unix 2.2

[Eric Feigenson]

Configuration:

BBC '386 Micronics motherboard
3Com 3C503 network card, external transceiver
ISC Unix Version 2.2  with: Streams, TCP/IP, Basic Networking & Core package

Problem: This machine can 'ping' itself, but can't seem to talk to the
rest of our network.  'ping'ing it from other machines yields no
response, either.  This hardware configuration used to work with Intel
Unix 1.0, but isn't working with this ISC setup.  We've tried every
interrupt address we can think of.  We *really* need this machine to
be talking to other machines on the net using TCP.

Does anyone have any ideas of what we could try to make this work?  Is this
a problem with ISC's Unix?  Is this a problem with us :-?

Please *E-MAIL* replies to: ericf at zurich.ai.mit.edu

Thanks in advance! ( and apologies in advance if this is a really stupid
question!)

-EricF