[comp.unix.i386] hardware flow control in 386 Unixes

rk@theep.boston.ma.us (Robert A. Kukura) (07/17/90)

Should I expect full-duplex RTS/CTS flow control to work correctly
with the following OSes on generic 386 AT-compatible systems,
particularly with a Telebit Trailblazer Plus locked at 19200 baud:

ISC 386/ix with the X6 update?

ISC Unix 2.2?

SCO Open Desktop?

The FAS driver on these same systems?


Thanks,
-- 
-Bob Kukura		internet: rk@theep.boston.ma.us
			uucp: spdcc!theep!rk

gemini@geminix.mbx.sub.org (Uwe Doering) (07/20/90)

rk@theep.boston.ma.us (Robert A. Kukura) writes:

>Should I expect full-duplex RTS/CTS flow control to work correctly
>with the following OSes on generic 386 AT-compatible systems,
>particularly with a Telebit Trailblazer Plus locked at 19200 baud:
>
>ISC 386/ix with the X6 update?
>
>ISC Unix 2.2?
>
>SCO Open Desktop?
>
>The FAS driver on these same systems?

As far as I know only FAS has RTS/CTS flow control that really works and
is capable of 19200 bps on more than one port at the same time (provided
you have installed NS16550A port chips).

You can use FAS on all of the above systems.

      Uwe
-- 
Uwe Doering   |  Domain   : gemini@geminix.mbx.sub.org
Berlin        |---------------------------------------------------------------
West Germany  |  Bangpath : ...!uunet!pyramid!tub!tmpmbx!geminix!gemini

david@csource.oz.au (david nugent) (07/20/90)

In <1990Jul17.121628.17613@theep.boston.ma.us> rk@theep.boston.ma.us (Robert A. Kukura) writes:

>Should I expect full-duplex RTS/CTS flow control to work correctly
>with the following OSes on generic 386 AT-compatible systems,
>particularly with a Telebit Trailblazer Plus locked at 19200 baud:

>ISC 386/ix with the X6 update?

Yes.


>ISC Unix 2.2?

Yes.

Both fairly good.

Some extracts from my /usr/spool/uucp/.Old/xferstats:

M (7/19-23:31:18) (C,201,5) [tty00] <- 94597 / 80.500 secs, 1175 bytes/sec
M (7/19-23:33:24) (C,201,7) [tty00] <- 141381 / 119.480 secs, 1183 bytes/sec
M (7/19-23:35:28) (C,201,9) [tty00] <- 141497 / 119.500 secs, 1184 bytes/sec
M (7/19-23:36:56) (C,201,11) [tty00] <- 97765 / 83.620 secs, 1169 bytes/sec
M (7/19-23:38:24) (C,201,13) [tty00] <- 92169 / 82.670 secs, 1114 bytes/sec
M (7/19-23:39:53) (C,201,15) [tty00] <- 97881 / 83.270 secs, 1175 bytes/sec
M (7/19-23:40:20) (C,201,17) [tty00] <- 24440 / 21.830 secs, 1119 bytes/sec
M (7/19-23:41:35) (C,201,19) [tty00] <- 81777 / 69.940 secs, 1169 bytes/sec
M (7/19-23:42:57) (C,201,21) [tty00] <- 89587 / 77.340 secs, 1158 bytes/sec
M (7/19-23:44:22) (C,201,23) [tty00] <- 91383 / 80.960 secs, 1128 bytes/sec
M (7/19-23:45:20) (C,201,25) [tty00] <- 61659 / 53.920 secs, 1143 bytes/sec

This is on a CONNECT FAST/UUCP.

I get around 1250 cps on a standard CONNECT FAST using rzsz (ZModem).


>SCO Open Desktop?

Don't know.


>The FAS driver on these same systems?

From a brief look at the sources, it appears to.

-- 
_______________________________________________________________________________
 Unique Computing Pty Ltd  Melbourne  Australia  -  Communications Specialists 
        david@csource.oz.au    3:632/348@fidonet    28:4100/1@signet           

rk@theep.boston.ma.us (Robert A. Kukura) (07/22/90)

In article <657@csource.oz.au> david@csource.oz.au (david nugent) writes:

   In <1990Jul17.121628.17613@theep.boston.ma.us> rk@theep.boston.ma.us (Robert A. Kukura) writes:

   >Should I expect full-duplex RTS/CTS flow control to work correctly
   >with the following OSes on generic 386 AT-compatible systems,
   >particularly with a Telebit Trailblazer Plus locked at 19200 baud:

   >ISC 386/ix with the X6 update?

   Yes.


   >ISC Unix 2.2?

   Yes.

The apparent consensus from all the email replies I have received is
that none of the mentioned 386 Unix versions pay attention to CTS.

   Both fairly good.

   Some extracts from my /usr/spool/uucp/.Old/xferstats:

   [...]

That does not mean that they do not work at high buad rates for UUCP
transfers, because UUCP has its own flow control and error detection
mechanisms.

In order to find out for sure whether my current system supported it,
I set my Telebit to use hardware flow-control and to lock its
interface speed at 19200 baud.  I then hooked another Telebit to a
terminal with the baud rate locked at 2400 baud.  I dialed into my
system from the terminal and established a PEP connection (high baud
rate).  When I cat'ed a large file, and watched the lights on the
system's Telebit, the CTS light would periodically go out, indicating
that the modems' buffers were full.  While the CTS light was off, the
SD light would stay on, showing that the system was still sending data
to the modem.

Unless there is some way that I do not know of to enable the CTS
support, or my serial card, modem or cable is defective, this proves
that ISC 2.0.2 with the X6 update does not do hardware flow control.
I am about to install the FAS driver and I expect that to fix it.

-- 
-Bob Kukura		internet: rk@theep.boston.ma.us
			uucp: spdcc!theep!rk