Xref: utzoo comp.sys.atari.st:12131 rec.music.synth:5036 Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!amdcad!sun!pitstop!sundc!seismo!uunet!mcvax!ukc!eagle.ukc.ac.uk!icdoc!tgould!awm From: awm@gould.stars.flab.Fujitsu.JUNET (Aled Morris) Newsgroups: comp.sys.atari.st,rec.music.synth Subject: Re: MIDI Networking Message-ID: Date: 26 Oct 88 15:36:16 GMT References: <3602@druhi.ATT.COM> <5080@saturn.ucsc.edu> <229@obie.UUCP> Sender: news@doc.ic.ac.uk Organization: Fujitsu Laboratories Ltd., Kawasaki, Japan. Lines: 24 In-reply-to: wes@obie.UUCP's message of 19 Oct 88 06:42:56 GMT >Bits 0 and 1 of the Control Register on the MIDI 6850 chip control a >"divider" for the input clock, determining the baud rate. The MIDI sets >these bits to 01, meaning divide the clock signal by 16. The clock to >the 6850 is 500 Khz, which gives us the MIDI speed of 31250 bps. > >If you reprogram these bits with 00, it tells the chip not to divide the >clock, giving you a clock of 500 Khz, which is adequate for a simple, >small network (like AppleTalk). Unfortunately, there is an opto-isolator in the circuit, and unless Atari have been extremely generous, I doubt very much that this part will be capable of running any faster than the original specification called for (i.e. 30k-ish). I don't think that you can simply bump up the clock frequency in order to improve the networking performance of the MIDI port. Aled Morris systems programmer mail: awm@doc.ic.ac.uk | Department of Computing uucp: ..!ukc!icdoc!awm | Imperial College talk: 01-589-5111x5085 | 180 Queens Gate, London SW7 2BZ