New subject: DEC prices and designs behind the times?

16 Apr 2001

To start with the switcher in question is 1987 design maybe earlier.  The MV2000 was
available in 87 or 88 if memory 
serves. And even if I'm wrong it's very definatly pre1990.

Dec often used standardized designs for years despite technology.
Regarding you comment on rotating technology.. your wrong. The biggest problem is that
often the older technologies were kept available too long or in service too long.  Add to
that usually
at least 50% of the rotating memory was not even DEC to start with.  Look at the DEC
designed products.

Allison
------Original Message------
From: "Richard Erlacher" &lt;edick(a)idcomm.com&gt;
To: classiccmp(a)classiccmp.org
Sent: April 16, 2001 3:03:26 AM GMT
Subject: Re: VaxStation 2000 PSU info needed

Back in the early '80's it wasn't uncommon for switchers to malfunction, or,
if
designed somewhat better, to fail to function at all, if no load was present.
This is consistent with DEC's practice of putting out 10-year old technology in
its "current" products.  Their rotating memory products were always at least
one, and often three, generations behind the "current" generation in other
makers' products.  That ensured maximal profits for DEC shareholders and maximal
bonuses for their execs, though it also ensured last-generation performance or
less for their users.

Dick

----- Original Message -----
From: "Brian Chase" &lt;bdc(a)world.std.com&gt;
To: &lt;classiccmp(a)classiccmp.org&gt;
Sent: Sunday, April 15, 2001 2:01 PM
Subject: Re: VaxStation 2000 PSU info needed

...
  On Sun, 15 Apr 2001, Richard Erlacher wrote:

  Is anbody intimate enough with the VaxStation
2000 to provide a couple
 of details?  Here's the deal: 
 Not really intimate with them, but I have used them to run NetBSD/vax and
 Ultrix.

  I snagged a VaxStation 2000 box some time back,
mainly for the PSU.
 It turns out that it has a couple of lines, on the 9-pin MOLEX main
 power output connector, the purpose of which is not clear.  There's
 one that seems to float at around -6 Volts DC, and another that floats
 at high-impedance, yet, when the one at -6 is pulled to 0 (gnd)
 through a resistor, the previously floating one suddenly has 9 volts
 or so.  Do these have a specific purpose that might serve some need
 I'm likely to encounter, or are they just for the DEC folks' features?
 Is there any way to capitalize on them, or should I just leave them
 alone?  All I'm after is fairly normal power output, with the added
 benefit of a fan and switch.  The +5 and bipolar 12's seem to work
 fine.  Spec's would be handy too, e.g. how much current can be drawn
 from each of the supplies and, perhaps from all of them at once? 
 I think (I'm not positive) this may be related to the nature of the power
 supply.  I've not actually used them for anything but powering the
 components which normally make up a VAXstation 2000.  They do have some
 interesting qualities, the main one being that they don't work right
 unless they've got a load on them.

 I've made the mistake of trying to run one diskless--which doesn't work.
 As soon as you add a disk drive, then the system goes through it's power
 up sequence without problem.  DEC did make a diskless version of the
 VS2000, but it had a big resistor board that plugged into the internal
 drive power cable.

 I'm sure someone here can address the actual reasons why the power supply
 behaves like this.  I think it's a trait of older switching PSUs.  But
 hopefully my "systems guy" observations provide some useful clues.

 -brian.
 --- Brian Chase | bdc(a)world.std.com | http://world.std.com/~bdc/ -----
 Being an open and honest guy, in the big "Occupation" box in the center
 of the sheet, I had written the same thing that's on my business cards.
 "Internet Legend".  -- K.