PDP-11 power requirements
ethan.dicks at gmail.com
Thu Feb 5 15:31:43 CST 2009
On Thu, Feb 5, 2009 at 4:19 PM, Paul Koning <Paul_Koning at dell.com> wrote:
>>>>>> "Ethan" == Ethan Dicks <ethan.dicks at gmail.com> writes:
> Ethan> My Unibus machines are racked, not loose, but I _thought_ that
> Ethan> the 11/44 and perhaps the 11/24 had a 20A 115V plug (i.e. --
> Ethan> | vs | | ). Mine go into a power distribution box at the
> Ethan> bottom of the rack and I haven't unplugged them in a long
> Ethan> time, but that's what I recall.
> If the particular config isn't too powerhungry you could replace the
> plug and plug it into a 15 amp circuit.
One could probably get away with that, but personally I'd prefer a 20A
circuit - the outlets are only a few bucks, but what might cost you is
the heavier wiring (12/2?) between the panel and the outlet.
Thinking further, I'm not as sure the 11/44 has a 20A plug, but I'm
more certain that the BA32 box that holds the CPU for my VAX8200 _is_
20A. I am not totally certain because I just slapped a 30A Hubbel
twist outlet on the side of my breaker box and swapped out the
breakers for the stove (I have a gas stove) for a pair of 110V
breakers - one powers the VAX. Since the wire run is from the breaker
to 6" away, there wasn't a lot of expense for heavy gauge wire.
I've since used that 30A outlet for an Alpha machine (medium sized,
one of the Futurebus+ models) as well as the 8200. It's rather handy
to have in the basement. It certainly would power any of the smaller
PDP-11s I have including a disk or two. Right now, my hungriest disks
are an RA81 and a Fuji Eagle (but only the RA81 is in that basement)
I spin up the RA81 first, let it settle, _then_ power on the VAX. I'd
love to find a VAXBI SCSI card, but such things were not cheap in the
day and I can't imagine they sold in very great numbers.
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