Path: utzoo!attcan!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.unix.i386
Subject: Re: On SCO Unix 3.2, Can a uugetty (for a modem) run at 19200 baud?
Message-ID: <3674@auspex.auspex.com>
Date: 17 Jul 90 17:55:04 GMT
References: <1371@beaudin.UUCP>
Distribution: comp
Organization: Auspex Systems, Santa Clara
Lines: 16

>This EXTA item rings a bell ( I think ), but not loud enough for me to hear.
>What is it?

A historical item.  The DEC DH-11 serial line mux had support for line
speeds up to 9600, plus two other speeds called "external A" and
"external B", which were to be driven by external clocks.  The UNIX tty
driver's line speed codes were basically those of the DH-11.

Later serial port hardware on various machines supported 19.2 and
sometimes 38.4 KB; the codes for "external A" and "external B" were
hijacked for those speeds on many UNIX systems.  I think Mr. Tucker is
saying that SCO UNIX 3.2 is one such system.  (Although I'm somewhat
surprised it doesn't grok "B19200" as well; the S5R3.0 "uugetty" code
appears as if it'll support that speed if "B19200" is defined in
<sys/termio.h>, and the S5R3.0 <sys/termio.h> defines both B19200 and
EXTA as the same code.)