[comp.music] Optocouplers for MIDI

ejbehr@rs6000.cmp.ilstu.edu (Eric Behr) (04/05/91)

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