AT bus Ethernet cards

[Michael P. Andrews]

We've used 3COM 3C505TP cards and they work fine with ISC UNIX (2.02 and
2.2). You can use the included 3C503 drivers. 
We don't use them on a 10BASET network (yet), we have a SynOptics LattisNet,
which is similar in wiring, but uses some different voltages and signals.
The 3COM 3C503-TP has several jumper options to configure the card for true
10BASET or a number of proprietary systems like ours.  We've had no problems
at all with the cards.
 
We have used 3COM 3C505 (256K 16bit) with no problems, but there are no ISC
drivers for them that I've seen.  We use those with Novell and Sun PC-NFS
The quirk with the RAM is that there's a 10-20 second delay on the
initialization of the network card driver. I suppose the CPU on the card has
to do a RAM checksum or somesuch.  I have heard that the 505's have caused
problems with UNIX, but I haven't personally had trouble (not using them
with UNIX).
 
We also have used Tiara twisted-pair cards in 8 bit and 16 bit versions. The
cards themselves are OK, but the drivers are AWFUL!!!.  The Novell drivers
don't use DMA. The PC-NFS drivers freeze up after 30 seconds.  We got the
ISC 2.02 driver to work only because we had UNIX guru on site to patch their
aborted install script.  Upon calling Tiara tech support, you receive a
response thus: Oh! you don't hav ethe latest driver - call our BBS. - I DID
CALL YOUR BBS!  - But the current driver is in a private area, here's how to
upload it, BTW it's a beta release, it's not stabile.... 
I finally talked to a programmer how was amazed that we got the ISC driver to
install and asked US how we did it!!!