Path: utzoo!mnetor!uunet!nuchat!sugar!karl
From: karl@sugar.UUCP (Karl Lehenbauer)
Newsgroups: comp.sys.amiga
Subject: Re: MIDI/GAMES/etc (was Re: Serial)
Message-ID: <1452@sugar.UUCP>
Date: 14 Feb 88 22:19:49 GMT
References: <2287@crash.cts.com> <945@polyslo.UUCP> <332@splut.UUCP> <318@stag.UUCP>
Organization: Sugar Land UNIX - Houston, TX
Lines: 32
Keywords: Serial, null modem, rs-232
Summary: Atari 520 ST MIDI ports are not compliant; personal computer
	 token ring nets without auto-drop-out are not viable

In article <318@stag.UUCP>, trb@stag.UUCP ( Todd Burkey ) writes:
> One nice thing is that by FOLLOWING the MIDI spec, Atari...

Note:  The MIDI connectors, at least on the 520 ST, are *not* compliant
with the International MIDI Association (IMA) MIDI specification.  The
MIDI 1.0 spec, as defined by the IMA, specifies that the three unused pins 
on the five-pin DIN connectors be left unconnected.  The ST puts power on 
at least one of these pins.  Granted, it can easily be hacked to be compliant,
and since (apparently) no other manafacturer has deviated from the spec, it 
hasn't fried anyone's hardware (yet).  Nonetheless, the ST does not comply
with the spec.

> ...Atari owners are
> able to use MIDI for networking. You just make a ring by going from
> the midi out of one machine to the midi in of another all the way
> around until you have completed the circle (just like musicians have
> had to do for years now hooking up their midi instruments to
> computers). 

I thought pretty hard about using MIDI as a token ring back when the ST
came out.  The problem is that *all* the machines in the ring have to be
up and running the network software or the net doesn't work.  On commercial 
token ring implementations, such as Apollo's, there is a relay on each 
workstation's network board that causes the machine to be electrically 
disconnected from the net when the machine is down or when it's up but 
the network software isn't running.  (Granted, there are pathological
conditions that can still break a net)  On a machine implemented the way 
the ST is; that is, a machine that needs to be rebooted a lot in the
normal course of it's operation, this is fatal for anything but hoyybist
get-togethers.
-- 
..!uunet!nuchat!sugar!karl, Unix BBS (713) 933-2440