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Path: utzoo!utcsrgv!info-mac
From: info-mac@utcsrgv.UUCP (info-mac)
Newsgroups: ont.micro.mac
Subject: Re:  wiring up an external disk drive
Message-ID: <4047@utcsrgv.UUCP>
Date: Thu, 26-Apr-84 01:56:06 EST
Article-I.D.: utcsrgv.4047
Posted: Thu Apr 26 01:56:06 1984
Date-Received: Thu, 26-Apr-84 04:15:23 EST
Sender: peterr@utcsrgv.UUCP
Organization: CSRG, University of Toronto
Lines: 23

Date: Wed, 25 Apr 84 13:21 PST
From: Bill Croft <uw-beaver!croft@Safe>
Subject: Re:  wiring up an external disk drive
To: info-mac@sumex
Cc: croft@Safe

Since we are still waiting on the 19 pin D connectors from AMP,
Nick Veizades, our hardware wizard, figured out this hack:  Take
a 20 cond ribbon cable and put a Berg on each end and another Berg
about 6 inches from one end.  Use the close pair to daisy chain from
the Mac CPU board to the internal drive and out a slot in the back
(over the top of the 19 pin D works fine).  Since wire # 14 is the
enable line (to the internal drive), cut this wire in the ribbon
cable.  Solder a pin on the other side of wire # 14 and stick it
in pin # 17 of the D connector (external drive enable).

The dual drive Mac works great.  A disk-disk copy takes about a 
minute with no disk swaps.  Programs using the "standard file"
file opening dialog (such as MacPaint) have a "drive" box that
toggles the current drive.  In the finder, new disks just appear
on the desktop when you insert them.