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From: ardai@bass.bu.edu (Michael Ardai)
Newsgroups: comp.periphs.scsi,comp.sys.amiga.hardware
Subject: Re: SCSI cabling
Message-ID: <72507@bu.edu.bu.edu>
Date: 17 Jan 91 02:43:11 GMT
References: <2251.AA2251@caleb>
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Followup-To: comp.periphs.scsi
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In article <2251.AA2251@caleb> jdp@caleb.UUCP (Jim Pritchett) writes:
-I am trying to make a cable to connect a Mac style DB-25 SCSI connector
-(on my A2090 controller) to the standard 50 pin rectangular style connector
-(NOT the Mac 50 pin Centronics style connector) on the bare SCSI drive.
-Most of the connections are obvious, but I have a couple of questions.
-
-1.  Is it ok to wire all the extra ground wires together?  (The 50 pin
-connector on the drive has lots more pins labelled ground.)
Yes.  If the Mac connector has more than 1 ground pin, split the grounds
evenly.

-2.  There is a pin on the DB-25 labelled 'TPWR'.  What does this mean?
-What should I connect it to?  (Or, should I leave that pin open?)
This pin is the 5 volt power supply for the termination sips..  It 
connects to pin 26 on the drive.  The controller card (and any other 
SCSI device) should have an isolation diode from 5v to TERMPWR so
multiple devices can source this power.

/mike
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\|/ Michael L. Ardai     ardai@bu-pub.bu.edu   ...!sun!teda!ardai (preferred)
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