Xref: utzoo comp.sys.m6809:919 comp.os.os9:190
Path: utzoo!utgpu!water!watmath!clyde!att!ihlpl!knudsen
From: knudsen@ihlpl.ATT.COM (Knudsen)
Newsgroups: comp.sys.m6809,comp.os.os9
Subject: Coco MIDI interface from the Modem Pak
Keywords: Coco, MIDI, music, hardware
Message-ID: <7309@ihlpl.ATT.COM>
Date: 20 Oct 88 17:42:16 GMT
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 21

We've seen a couple articles about hacking the Modem Pak
(now on sale for $30) to drive an external modem (like an RS232 Pak).

Another trick would be to hack it to a MIDI synthesizer driver
and receiver.  This would require changing the crystal to some
multiple of 1.000 MHz (1,000,000 Hz / 32 = 31.25 KBaud for MIDI).
Also replacing the modem chip with a little hardware (couple resistors
and an opto-isolator) to send and receive MIDI current loop.
And of course mounting the two DIN jacks.

Given that only one company (Intercomp Sound in Rochester, NY)
is selling MIDI Paks, for around $90, rolling your own from a
$30 modem pak sounds like a good use for a rainy weekend.

Of course a similar conversion applies to the RS232 Pak, tho it's
much more valuable as-is than is a 300 Baud Modem Pak.
	mike k
-- 
Mike Knudsen  Bell Labs(AT&T)   att!ihlpl!knudsen
"Lawyers are like handguns and nuclear bombs.  Nobody likes them,
but the other guy's got one, so I better get one too."