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From: rk@theep.boston.ma.us (Robert A. Kukura)
Newsgroups: comp.dcom.modems,comp.unix.i386
Subject: Re: hardware flow control in 386 Unixes
Message-ID: <1990Jul21.171709.2496@theep.boston.ma.us>
Date: 21 Jul 90 17:17:09 GMT
References: <1990Jul17.121628.17613@theep.boston.ma.us> <657@csource.oz.au>
Organization: Theeptronics
Lines: 49
In-Reply-To: david@csource.oz.au's message of 20 Jul 90 14:21:49 GMT

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