Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.dcom.modems
Subject: Re: New "Alternate Connector For Use With ANSI/EIA-232-D"
Summary: midi interface
Message-ID: <1725@neoucom.UUCP>
Date: 20 Sep 89 11:10:56 GMT
References: <870.251007A2@zswamp.fidonet.org> <328@gp.govt.nz> <8539@hoptoad.uucp> <45725@bbn.COM>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 33


The recent articles about cobbling up a universal interface are
pretty close to the midi specification used by manufacturers of
electronic musical instruments and controllers.

The midi specification uses 5 pin DIN connectors for everything.
All devices have female connectors.  All cables have male
connectors on both ends.  Every cable is essentially a null modem,
with the leads cross-connected.

Midi standardizes everything to the same baud rate too: ~31.5
Kbit/sec.  I don't particularly like a rate that low, but... at
least that isn't a worry.  There are five leads:  Txdat, Rxdat,
Txclock, Rxclock, and ground.  In theory, I suppose you could use a
nonstandard baudrate and sync to the clock.  As it stands now, the
clock leads are optional.  I think midi uses a low data rate
because inexpensive optical isolators are used as line receivers.

It's too bad that genderless connectors weren't desgined for midi,
as there are many times I've wound up with two short midi cables
when I actually wanted one long cable.

The Atari ST series computers are supplied with a midi connector
port as standard equipment.  Not all uses are for music.  There are
several Atari games out that use the midi connector as a poor man's
network for multi-machine play.

It's too bad that we're still saddled with RS232-C that dates from
about 1962.  ...and I hate those 9-pin DE connectors on AT machines
even more than 25 pin DB connectors!


Bill