value of classic DEC machines?

From: Doug Carman <>
Date: Mon Oct 29 19:02:22 2001

Tony Duell wrote:
> My guess is that if you take an 11/70 CPU, leave one 10.5" bay empty
> above the CPU, then put 2 memory boxes in the top 2 rack bays, the
> machine will be fine. If you are worried, rig up some air deflectors and
> a fan in the bay immediately above the CPU box.
Actually, I found removing the 861C power controller from under the CPU,
and getting rid of all the cables that were stuffed under it made the
biggest difference for exhausting heat from the CPU itself.
> If you've got the space for 3 racks then, sure it's nice to have the
> stuff spread out. But my experience is that empty rack bays attract
> BA11-K expansion boxes, RK05/RL drives, and so on... You keep on finding
> other things to add to the machine
Isn't that the point? Actually, my two RL02 drives are in the bottom of
the two TU81 tape drive cabinets that sit on either side of the 11/70.
That way I have more room to put future goodies in the H960 racks. :)
> Yes, some rules have to be followed. Don't put an RK05 or a BA11-K
> immediately above an BA11-F (11/45 or 11/70 CPU). It will overheat. But
> other rules cna most certainly be broken with no problems.
I can also say that some of this depends on where you are. Since I am
in Florida, heat removal from any interior space can be a problem.
Making it easier to get airflow through the PDP-11 cabinets makes it
much easier to get heat out of the room. Even at that, A/C can find it
hard to keep up in the warmer months. This time of year is when I can
actually think of running the system for a period of time without it
getting too hot, or costing a fortune to cool. It already costs a
fortune just to run.

Doug Carman
Received on Mon Oct 29 2001 - 19:02:22 GMT

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