Subject: Re: VS2000 PS quirk? [Was Re: Anyone running on VS2000 w/small
To: Brian D Chase <bdc@world.std.com>
From: Bryan A. Ignatow <ignatow@sprintparanet.com>
List: port-vax
Date: 05/26/1998 00:44:36
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At 17:44 5/25/98 -0700, Brian D Chase wrote:
>
> [...]
>
>I guess the PS really wants something to act as a load on those power
>connectors for the disk drives.  I don't know that this is normal behavior
>or not, but it seems like I can reproduce the problem.  We used to have a
>very large number of VAXstation 2000s at my college, and I'm pretty sure
>that we used them as diskless nodes on a VMS cluster with our VAX 6000. I
>remember this, because my roommate and I were very disappointed when we
>could only find one spare VAXstation 2000 with a disk drive for running
>an Ultrix system.  All the other VS2000s we could lay our hands on didn't
>have any drives.
>
>Can anybody more familiar with VS2000s or maybe even electrical power
>systems shed some light on perhaps why a VS2000 would need a load on the
>drive power connectors to operate normally?
>

I don't know why the VS2000 needs a load on the power supply but it does.
I don't remember seeing diskless models appearing on the scene until later
on in their life (by the time a full load of OpenVMS's size outpaced the
RD5x family of drives).  I do remember mounting a board packed with
resistors (big ugly ones) into a trio of VS2000's to substitute for the
drives (the board had three or four columns of resisters and a power jack
just like the back of a drive; the board was about the size of a half
height Q-Bus card, even though there is no relation between them... I just
remember them being about that size).  You might see if anyone has a clue
as to the DEC Part Number for the load board (which is what I believe they
were called).  They were pretty hard to get ahold of 6 years ago when I put
in those three, so I would guess they are going to be pretty scarce now.  A
drive in there without the drive cable attached will work pretty good as
long as the drive keeps spinning and does not go up in smoke.


- ---
Bryan A. Ignatow                           Sr. Technical Analyst
ignatow@sprintparanet.com                  Sprint Paranet
(Intranet Only) http://general.srv.paranet.com/~baignato

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