Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site cvl.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!umcp-cs!cvl!hsu From: hsu@cvl.UUCP (Dave Hsu) Newsgroups: net.music.synth Subject: Re: Re: rs232 midi interfaces Message-ID: <49@cvl.UUCP> Date: Mon, 18-Feb-85 14:02:36 EST Article-I.D.: cvl.49 Posted: Mon Feb 18 14:02:36 1985 Date-Received: Thu, 21-Feb-85 03:56:11 EST References: <870@bnl.UUCP> <2560@mcnc.UUCP> Distribution: net Organization: Computer Vision Lab, U. of Maryland, College Park Lines: 24 > In article zadco@ssc-vax.UUCP (Rick Fairfield) writes: > > >MIDI requires over 30000 bits/sec. RS232 usually runs at most 19200 baud so, > >as you can see, MIDI is a problem over RS232. > > zzzzadco > > While the problem isn't trivial, It should be possible to send/translate > RS232->MIDI in a fairly straightforward way. 32K bits/sec translates > roughly to 3200 baud (as baud is used in lay terminology.) Actually 32K bits/sec translates to 32K baud more or less. In the midi sense, it actually means 30.25(?)K baud. For this reason, most RS 232 ports cannot be run directly to midi because their baud-rate generators cannot handle this data rate. Most popular uarts (i.e. 6850 ACIA, AY5-1013) may be run at this speed, although it is near the maximum rating for some. In this way, the Apple Macintosh can be used to run midi devices, with little more than some opto-isolators for the current-loop interface. =Dave Hsu= "If only we'd had a cat like that..." (301) 454-4526 ARPA: hsu@cvl hsu@umd2 USnail: Computer Vision Laboratory CSNET: hsu@cvl Center for Automation Research BITNET: hsu@umd2 University of Maryland UUCP: {seismo,allegra,brl-bmd}!umcp-cs!cvl!hsu College Park, MD 20742