Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!nuchat!sugar!karl From: karl@sugar.UUCP (Karl Lehenbauer) Newsgroups: comp.sys.amiga Subject: Re: Amiga memory and serial questions Message-ID: <1229@sugar.UUCP> Date: Sat, 5-Dec-87 15:12:53 EST Article-I.D.: sugar.1229 Posted: Sat Dec 5 15:12:53 1987 Date-Received: Fri, 11-Dec-87 05:35:03 EST References: <4558@pyr.gatech.EDU> <1303@saturn.ucsc.edu> Distribution: na Organization: Sugar Land UNIX - Houston, TX Lines: 21 Keywords: slow ram, fast ram, MIDI > In article <4558@pyr.gatech.EDU> gt4785b@pyr.UUCP (David Carter) writes: > >And since I didn't get any reply to my question "What bit rates are available > >on the serial port?" can somebody at least tell me what the MIDI bit rate is? > >I've heard 'guesses' of 32,768 and 30,500, but my communications text says > >that 20,000 bps is a practical upper limit for RS-232. MIDI runs at 31250 bits per second. That is one million divided by 32, a useful number for people doing dedicated MIDI interfaces (i.e. ones that only run at the MIDI clock rate) Note that this is still an asynchronous protocol; two framing bits are transmitted per byte of data. MIDI is not RS-232. RS-232 uses +/- 12 volts for ones and zeros. MIDI uses five and zero volts. Also note that MIDI cable lengths over 50 feet are not recommended and MIDI does occasionaly drop a bit. Since it's not an error free protocol (other than certain manafacturer's system exclusive formats and the sample dump standard) that can cause all sorts of problems, the most common of which is hanging notes, but that's another story for another time. -- ..!uunet!nuchat!sugar!karl Unix BBS (713) 933-2440