Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!cornell!rochester!bbn!spdcc!merk!alliant!rosenkra
From: rosenkra@Alliant.COM (Bill Rosenkranz)
Newsgroups: comp.sys.atari.st
Subject: Re: MIDI Thru
Message-ID: <2113@alliant.Alliant.COM>
Date: 14 Jul 88 06:00:17 GMT
References: <880713183142A48.AFUJ@Mars.UCC.UMass.EDU>
Reply-To: rosenkra@alliant.UUCP (Bill Rosenkranz)
Organization: Alliant Computer Systems, Littleton, MA
Lines: 35

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In article <880713183142A48.AFUJ@Mars.UCC.UMass.EDU> jsd@UMass.BITNET (Jonathan S. Drukman) writes:
->Hi there.  Any of you technically oriented net people into MIDI?
->What I'm specifically interested in is making the ST perform a MIDI
->Thru function. 

there are no (documented) ways of splitting out/thru midi signals. you are
correct in saying the ST's midi out jack contains both out and thru signals.
it is a simple matter to make a "Y" cable seperating out from thru (i made
my own after a quick trip to radio shack). here are the pin outs:

MIDI OUT

pin	function
---	------------------------------------
1	THRU transmit data
2	shield ground (i think case gets grounded as well)
3	THRU return
4	OUT transmit data
5	OUT return

just take 1 to the new jack's pin 4 and 2 to new 5. make sure 2 goes to ground
BOTH jacks.

BTW midi in is:

pin	function
---	---------------------------
4	IN receive data
5	IN return

pin 2 (according to IMA) does not need to be grounded (atari HW doc indicates
no grounding as well). not being a h/w person, i don't know what effect
grounding would have.

-bill