Help Please with Telebit and SCO RTS/CTS Setup?! (LONG)

[Connor MacLeod]

Hi Mark  (the original author of the article I'm replying to)
Hi Netlanders...

(For those who missed Marks article: he's got troubles when trying to
 get SCO Unix 3.2.1 (ODT) driving his TBIT with RTS/CTS flow full duplex
 at 19200 bd...)

I just had the same problem. It's just as the guy at Telebit said:
using the hardware handshake only in half duplex mode is ok for 99%
of all the data transmission. But...

I've got some dropouts when polling large files (it's the remaining 1%
I bet :>) and I decided to set up RTS and CTS flow. It didn't work at all.
<sigh>

I asked a few people around here and I was told to exchange the 16450
chips on my serial cards by 16550 ones. The NS16550A is able to run in
16 byte FIFO mode and this buffer stores the byte(s) in case the system
is on havy load and not able to get all the data from the modem in time.

The next step is to replace the original sio driver of the SCO Unix by
a public domain driver called FAS 2.08 (I can mail/post more information
about this driver if someone is interested in).
This driver is able to do the RTS/CTS flow in full duplex mode 100%!

Well. I haven't got the time to install the FAS driver so far but from
the moment on I replaced the 16450s all works fine (about a month now).

If anyone decides to replace his serial chips, too, make sure to get the
16550A! The 16550 chips have a hardware bug and the FAS driver will not
work with them...

I hope this is of some help :)

Rgds

-- 
Uwe Obst             # {connor|macleod}@cmllab.rgb.sub.org
(aka Connor MacLeod) # "Trust me, I know what I'm doing!" -- Sledge Hammer