Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!cmcl2!phri!roy From: roy@phri.UUCP (Roy Smith) Newsgroups: comp.bugs.4bsd Subject: Re: TANDEM mode bugs in 4.3bsd Message-ID: <2554@phri.UUCP> Date: Mon, 12-Jan-87 12:45:19 EST Article-I.D.: phri.2554 Posted: Mon Jan 12 12:45:19 1987 Date-Received: Tue, 13-Jan-87 04:36:48 EST References: <973@tymix.UUCP> <2439@sdcsvax.UCSD.EDU> Reply-To: roy@phri.UUCP (Roy Smith) Distribution: world Organization: Public Health Research Inst. (NY, NY) Lines: 20 Summary: shades of v6! In <2439@sdcsvax.UCSD.EDU> brian@sdcsvax.UCSD.EDU (Brian Kantor) writes: > Very very few devices queue an incoming XOFF, which means that extra > ones don't hurt and are likely more often to help. [...] > What may have prompted this is using terminal i/o with TANDEM set to > communicate with some other computer system which does not obey the same > XOFF/XON semantics as Unix does. CP/M systems, for example, use XOFF to > stop output, but will restart it again on ANY character, including > another XOFF. A historical interest note: on vanilla v6 UNIX, XOFF was a toggle; send one XOFF to stop output, another to restart it. Given that v6 didn't come with a pager program, the small amount of time saved by not moving your fingers on the keyboard was important at 9600 baud. One of my first kernel hacks was to add "normal" XON/XOFF processing to the v6 tty driver. -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016 "you can't spell deoxyribonucleic without unix!"