uucico problem with flow control

Mark W. Snitily mark at zok.UUCP
Wed Aug 16 17:44:29 AEST 1989

In article <4255 at ursa-major.SPDCC.COM> dyer at ursa-major.spdcc.COM (Steve Dyer) writes:
>You can't use ^S/^Q flow control with uucico, since the 'g' protocol
>expects a transparent 8-bit channel.  This isn't a problem with the
>TB+ in PEP mode since ^S/^Q won't be sent, but it will be a problem
>at slower speeds.  I assume you have the TB+ fixed at 9600 or 19.2k baud.
>Some people (not me) have reported success with a fixed baud rate and
>^S/^Q turned off on the modem.  Alternately, you can reconfigure the
>Telebit to use the speed of the incoming modem.

The original posting was regarding uucico alarms.  Since this was the
same problem I had, thought I'd share some useful info.  Vernon Schryver
(vjs at calcite.UUCP) told me about the following solution.  Thanks Vernon!

   My TB+ is fixed at 19.2k baud and the ^S/^Q is turned off.  Running
386/ix 2.0.1 on a noname 25MHz clone.  Had a typical serial I/O card
with 16450 UART chips.  In this configuration uucico was reporting a
multitude of alarms and (when receiving) the throughput was only in
the 400-500 chars/sec range.

   I'm now receiving in the range of 800-1100 chars/sec with no uucico

   Here's the trick:

   (1) Replace the 16450 UART chip(s) with 16550A chips.  (Here in silly
valley the 16550A costs about $14.00 at a local electronics store.)
Hopefully your serial card has sockets and you can simply replace the
UART chip.  If not, either try some fancy soldering (40 pins) or else
get a cheap card with sockets.  The data sheet for the 16550A is in
National Semiconductor's "Microcommunication Elements Databook."

   (2) Replace the ISC 386/ix asy device driver with Jim Murray's PD
device driver.  It was posted a few months ago in comp.unix.microport.
His address as listed in the README file is:
   Jim Murray              encore!cloud9!jjmhome!jjm
   2 Mohawk Circle         harvard!m2c!jjmhome!jjm
   Westboro Mass 01581     jjm%jjmhome at m2c.m2c.org
   USA                     voice (508) 366-2813

   His device driver was written for uport, but I've installed it on 386/ix
2.0.1 with no major problems.  You have to read up on how to install a new
386/ix device driver because installation on uport is totally different.

   Hope this speeds up a few 386 TB+ configurations out there.

-- Mark W. Snitily
   (408) 252-0456 (voice with answering machine)
... {amdcad, ardent, athertn, claris, daisy, limbo, mips, sgi, voder} !zok!mark

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