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- Path: sparky!uunet!sun-barr!olivea!sgigate!odin!twilight!zola!zuni!anchor!olson
- From: olson@anchor.esd.sgi.com (Dave Olson)
- Newsgroups: sci.electronics
- Subject: Re: Need Help With SCSI Device
- Message-ID: <pqtsceo@zuni.esd.sgi.com>
- Date: 14 Sep 92 05:52:23 GMT
- References: <1992Sep13.151356.1307@mccc.edu>
- Sender: news@zuni.esd.sgi.com (Net News)
- Organization: Silicon Graphics, Inc. Mountain View, CA
- Lines: 25
-
- In <1992Sep13.151356.1307@mccc.edu> pjh@mccc.edu (Pete Holsberg) writes:
- | The Trantor MiniSCSI converter gets its power from pin 38 of the SCSI
- | device it plugs into, in this case, a WangDAT 1300. However, the W'DAT
- | poops out only 2V amd the M'SCSI wants 5.
- |
- | Could someone tell me about pin 38 before I start futzing around with 5V
- | power supplies and piggyback connectors? :-)
-
- Pin 38 on the centronics connector is termpower, on ribbon cables
- it is pin 26. Only one device on the SCSI bus is required to
- supply termpower, and not all devices can be jumpered to supply it
- (many assume the host will supply it). When present, it only
- needs to exceed 4.25 volts under SCSI-2 (not 5), and I think it
- was only 4 v required under SCSI-1. Since a diode is also required
- when termpower is supplied, you will seldom see 5 v on the termpower
- line. Presumably the Trantor is able to accept that, since from all
- accounts it mostly works.
-
- As I recall, the WangDAT units *can* be jumpered to supply term
- power, but you'll have to check your manual to see if this is true,
- and which jumper(s)/switches to change.
- --
- Let no one tell me that silence gives consent, | Dave Olson
- because whoever is silent dissents. | Silicon Graphics, Inc.
- Maria Isabel Barreno | olson@sgi.com
-