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From: dag@chinet.UUCP
Newsgroups: comp.sys.amiga,comp.sys.atari.st
Subject: Re: Amiga and MIDI
Message-ID: <1931@chinet.UUCP>
Date: Tue, 1-Dec-87 00:06:11 EST
Article-I.D.: chinet.1931
Posted: Tue Dec  1 00:06:11 1987
Date-Received: Thu, 3-Dec-87 23:40:47 EST
References: <447@nuchat.UUCP> <32160@auc.UUCP> <528@otto.COM> <4567@pyr.gatech.EDU>
Reply-To: dag@chinet.UUCP (Daniel A. Glasser)
Organization: Chinet - Public Access Unix
Lines: 39
Keywords: MIDI Amiga Atari ST
Xref: utgpu comp.sys.amiga:10922 comp.sys.atari.st:6121

In article <4567@pyr.gatech.EDU> gt4785b@pyr.UUCP (David Carter) writes:
+ ...
+The midi "interface adaptor" for the amiga consists of:
+    a DB-25 plug, a DB-25 socket, 4 DIN sockets, 2 toggle switches,
+    an optiosolator, and an op-amp.
+
+In other words, the only thing not already MIDI about the port on the back of
+the Amiga is that it's a DB-25 instead of a DIN.  The op-amp and optoisolator
+just make it safe (i.e. buffering).  But as far as software is concerned, ANY
+midi "adaptor" for the amiga will look the same.
+ ...
+David Carter

Actually, I suspect that the op-amp is to make a current loop out of an
EIA (RS-232 style) connection, the opto-isolator is for protection.

MIDI is a serial 5ma current loop with passive receivers, active
transmitters.  The op-amp can be used to convert EIA to current loop for
the transmitter, the opto-isolator can be used to read the received data.

I'm not sure how the Amiga printer port is configured, and how the MIDI
devices are accessed from the program, but there are MIDI interfaces on
the market with different features, and this would seem to indicate that
not all Amiga MIDI adaptors are created equal from a programming standpoint.

Does the Amiga OS support MIDI devices?  The ST OS does.

A question that must be asked before buying either machine to be part of
a MIDI set-up:  Does the software that I want exist for this machine?
If the answer is no, you need to look into whys and whens.  Don't let
a bunch of people from either fan club badmouthing the other machine
influence you too much.  In most cases, neither party knows of what they
speak.
-- 
					Daniel A. Glasser
					...!ihnp4!chinet!dag
					...!ihnp4!mwc!dag
					...!ihnp4!mwc!gorgon!dag
	One of those things that goes "BUMP!!! (ouch!)" in the night.