Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site brl-tgr.ARPA Path: utzoo!linus!decvax!tektronix!hplabs!hao!seismo!brl-tgr!internet!Mike Gallaher From: Mike Gallaher Newsgroups: net.unix-wizards Subject: Re: unix & real time -- is a rewritten UNIX still UNIX? Message-ID: <5913@brl-tgr.ARPA> Date: Mon, 19-Nov-84 21:05:31 EST Article-I.D.: brl-tgr.5913 Posted: Mon Nov 19 21:05:31 1984 Date-Received: Wed, 21-Nov-84 05:14:02 EST Sender: news@brl-tgr.ARPA Organization: Ballistic Research Lab Lines: 20 From: Bill Shannon [handling] 9600 baud asynchronous input with little or no hardware buffering. On the Sun our approach to guaranteeing that we could service the interrupt as soon as possible was to make the UARTs interrupt at a priority higher than the system used for anything else, even the clock. I've suspected for a while that that is the reason why the time of day clock on our Sun 120 loses up to an hour or more a day, depending on "system activity", which turns out to be "serial port usage". We have two 9600 baud ports and a 1200 baud uucp port. The hardware clock is accurate, but the system time is set by it only at boot time. mike gallaher ....!sun!sunrise!unipress!mg mg@rutgers -------