Path: utzoo!utgpu!water!watmath!clyde!cbosgd!mandrill!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.sys.amiga
Subject: Re: MIDI/GAMES/etc (was Re: Serial)
Summary: Amusing feedback effects via MIDI
Keywords: Serial, null modem, rs-232
Message-ID: <982@neoucom.UUCP>
Date: 28 Jan 88 14:29:32 GMT
References: <2287@crash.cts.com> <945@polyslo.UUCP> <332@splut.UUCP> <318@stag.UUCP>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 22


You can get some really funky feedback effects when two
synthesizers (or other MIDI devices) are connected in a ring
fashion with each synth's OUT connected to the other's IN.  Of
course, each synth has to be receiving and transmitting on the same
channel.  Feedback occurs because the local CPU in each synth has
to pick up the data look at it, and insert any of its own MIDI
events in the data stream; a slight delay is generated as the data
takes a trip though the CPU.  The MIDI THROUGH port should have no
delay, as by definition it is merely a repeater socket.

The lesson here for musicans is that if you are driving several
synthesizers from one MIDI out, it is best to connect them in
parallel, so that a time delay isn't imparted to notes that should
be coming out of several synths simultaneously.  Note that the
THROUGH port effectively connects them in parallel.

The lesson for programmers is that is makes a good token ring
approach (albeit slow in the case of MIDI 32.5 KBPS), and this has
been neatly exploited in the ST's Midi Maze program.

--Bill