Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!mit-eddie!genrad!decvax!decwrl!nsc!voder!apple!lsr From: lsr@apple.UUCP (Larry Rosenstein) Newsgroups: comp.sys.mac Subject: Re: Programming for High Baud Rates Message-ID: <651@apple.UUCP> Date: Wed, 22-Apr-87 13:38:05 EST Article-I.D.: apple.651 Posted: Wed Apr 22 13:38:05 1987 Date-Received: Fri, 24-Apr-87 05:23:02 EST References: <441@wang.UUCP> <8602@clyde.ATT.COM> <648@apple.UUCP> Reply-To: lsr@apple.UUCP (Larry Rosenstein) Organization: Advanced Technology Group, Apple Computer Lines: 23 Keywords: SCC, programming, compatibility, yuck In article <648@apple.UUCP> huxham@apple.UUCP (Fred Huxham) writes: >2) Most code that talks directly with communication hardware has timing >sensitive loops (at least mine did). Don't assume the speed of the >CPU you're running on. At startup you can execute a DBRA loop a good number >of times and see how long it takes you. From this you can calculate how >fast your CPU is and adjust all of your timing sensitive loops accordingly. Inside Macintosh Volume V defines a new global variable called TimeDBRA, which defines the speed of the processor in this way. This is discussed in the Start Manager chapter. Larry -- Larry Rosenstein Object Specialist Apple Computer AppleLink: Rosenstein1 UUCP: {sun, voder, nsc, mtxinu, dual}!apple!lsr CSNET: lsr@Apple.CSNET