Looking for VAX6000 items

Bill Degnan billdegnan at gmail.com
Wed Jul 14 08:39:23 CDT 2021

The LSSM, VCFed and System Source acquired a large collection of VAX
hardware couple of years ago and divided it up for their various museums
(6000?  7000?).  There is very little about it online, but I have
seen the portions that made it to vcfed and System Source.  If it wasn't a
very large 6000 array, it was something contemporary and there was a
plethora of terminals, parts, cabinets that would have been
6000-compatible.  You should ask someone at VCFed to take a look at what
they have in the warehouse.  Also the Rhode Island computer museum may have
some 6000 stuff, I was just there.


On Wed, Jul 14, 2021 at 9:21 AM Paul Koning via cctalk <
cctalk at classiccmp.org> wrote:

> > On Jul 13, 2021, at 11:34 PM, Chris Zach via cctalk <
> cctalk at classiccmp.org> wrote:
> >
> >> When we got an 8530 at work in the early 90s (needed a machine with a
> >> Nautilus bus for specific hardware testing), it was definitely a
> >> 3-phase machine and since we were in an industrial setting, I just
> >> tapped into our panel at the back of the warehouse and wired up a
> >> 3-phase outlet for it.  It never sat on our datacenter floor as a
> >> result, but it really only ever had one purpose and that wasn't a
> >> daily driver.  Too much power, too much heat for so few employees (at
> >> that stage of the company).
> >
> > Interesting. Were the power supplies 3 phase input? Like you I have
> noticed that most pdp and vax gear just pull 120 volt legs off the 3 phase
> to balance power loads. So you can run them on a couple of 120 circuits.
> Outside of say the RP07 (which is a real 3 phase motor)
> A number of the large disk drives use 3 phase motors; RP04/5/6 are
> examples as well.
> Three phase motors won't run on single phase power without help from run
> capacitors.  (There is no such thing as "two phase power" -- 220 volts is
> single phase, balanced.)
> If the issue is motors, a "variable frequency converter" will do the job
> easily.  I have suggested in the past that three phase power supplies could
> run from those, but others have pointed out I overlooked some issues.  So
> that's probably not a good idea.
> If you need three phase power to feed power supplies or other non-motor
> power consumers, the best answer is probably a "rotary converter".  You can
> find those in machine tool supply catalogs.  Basically they are a three
> phase motor equipped with run capacitors so they can be fed single phase
> power; the three phase power needed is then taken off the three motor
> terminals.  You can think of these as rotary transformers -- dynamotors in
> a sense, for those of you who remember electronics that old.  :-)
> Don't look at "static converters" -- those are only for motors, it seems
> they aren't much more than run capacitors in a box.  They won't help you
> for anything other than a motor, and even for motors they aren't very good.
>         paul

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