Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!sgi!vjs
From: vjs@rhyolite.SGI.COM (Vernon Schryver)
Newsgroups: comp.unix.microport
Subject: RTS/CTS flow control
Keywords: asy(7)
Message-ID: <17563@sgi.SGI.COM>
Date: 19 Jul 88 18:15:38 GMT
Sender: daemon@sgi.SGI.COM
Organization: Silicon Graphics Inc, Mountain View, CA
Lines: 16

Microport says that the asy driver in V/386 does not support RTS/CTS
flow control.  Experiments with a break-out box support that statement.
How do you use a Trailblazer or other high speed async device without
'hardware' flow control?  Obviously, XON/XOFF is not so hot when you
have binary data, so I didn't bother to see if that works.

Experiments with a break-out box suggest that when more than one process
opens /dev/tty00, the <<first>> close(2) drops DTR & RTS.  Did I get it
wrong?  Isn't this a bug?

Microport says that DOS programs under Merge which want to use the COM
ports run just fine with 'a=com1'.  I've found that input locks up under
load, and that output either garbles or drops characters.  What am I
doing wrong?

Vernon Schryver
vjs@sgi.com