[comp.os.msdos.programmer] TOPS DOS 2.1 and 19.2Kbps RS-232

cgordon@vpnet.chi.il.us (Crash Gordon) (12/07/90)

I need to run a 19.2 Kbps serial port on a 386DX/16 machine which is also a
server for TOPS DOS 2.1.  The network uses only PCs, and these PCs all
use the TOPS Flashcard.  Everything works fine, until a client accesses
the server disk, at which point some of the characters coming in the serial
port are lost.

Since I really only need to pay attention to the serial port at certain
known times, what I'd like to do is suspend TOPS for a few milliseconds once
in a while, while I attend to the serial port.  Is there a way to put a jam
on the network without bombing TOPS?  Would a jam do what I want (to free up
the server)?

The server is a given; solutions like "use a faster machine" are out.  The
current fix is to throw some hardware at the serial line, and try to buffer
it externally.  I'd like to solve this in software, if possible.

I called TOPS, and their answer was that you can't suspend TOPS like that. 
(You can unmount all drives at all clients, then issue TOPS PAUSE at the
server, but that doesn't quite have the granularity I'm after... :-)  I
suppose I can accept this if it's really so, but on the off chance that
someone has tackled it and won...

-----------------------------------------------------
Gordon S. Hlavenka            cgordon@vpnet.chi.il.us
Disclaimer:                Definitely not a TOPS guru