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From: ejbehr@rs6000.cmp.ilstu.edu (Eric Behr)
Newsgroups: comp.music
Subject: Optocouplers for MIDI
Message-ID: <1991Apr05.015937.2875@rs6000.cmp.ilstu.edu>
Date: 5 Apr 91 01:59:37 GMT
Reply-To: ejbehr@rs6000.cmp.ilstu.edu (Eric Behr)
Distribution: na
Organization: Central Illinois Surfing Club
Lines: 16

First, this may be a wrong group, but I couldn't find any better one...
I spent an evening putting together a MIDI interface designed by Kent
Boortz (boortz@sics.se; I forget where I got the nice PostScript file with
the plan). Instead of the Sharp PC900 optoisolator which he recommends, I
used an MCT-2 (GE?) which I saw used in other interface designs.
Then I saw an ad with MIDI-related stuff, which lists a "hard to find
essential component, the PC900 chip". As far as I can tell, the PC900 has
the same pinout as most standard chips, including the MCT-2; it may be
faster, but the interface I tried to make has 500MHz clock, so any
reasonably fast optocoupler should work, no? Is PC900 really "essential"?

Needless to say, my interface doesn't work  :-(  I don't have a scope, so I
can't say exactly what's going on. Thanks for any help you can offer.  E.
-- 
Eric Behr, Illinois State University, Mathematics Department
Internet: ejbehr@rs6000.cmp.ilstu.edu    Bitnet: ebehr@ilstu