Looking for two DEC H445 power bricks for PDP 11/40 project

Paul Anderson useddec at gmail.com
Thu Sep 20 01:24:18 CDT 2018


I also saw some notes about different wiring harnesses for different serial
numbers. A lot to be careful with.

On Thu, Sep 20, 2018 at 1:22 AM, Paul Anderson <useddec at gmail.com> wrote:

> I grabbed a 11/60, 11/35 system manual. wanting to see hot power was set
> up in the BA11-D and -K, only to find it dealt with the BA11-F only.
>
> It does state the H754 in used with the MF11-U/UP. needless to say, there
> are different plugs for slot "E" and possibly a change or a jumper.
>
> I will look for a 11/35 book specifically next time I go downstairs.
>
> My 11/40 does have 2 H745s in it. I see no reason to use both at this
> point. I think one can supply enough current unless you overload it with a
> bunch of 8K core.
>
> I plan on putting either 8 16K core stacks in(for winter only) or an
> MS11-LD (256KB).
>
> Pierre, a lot of my bricks are buried. I'll try to did them out tomorrow.
>
> Thanks, Paul
>
> On Wed, Sep 19, 2018 at 4:09 PM, Eric Smith via cctalk <
> cctalk at classiccmp.org> wrote:
>
>> On Tue, Sep 18, 2018 at 8:27 AM, Noel Chiappa via cctalk <
>> cctalk at classiccmp.org> wrote:
>>
>> > (Note that if you have an old
>> > machine/harness, there's a jumper you have to add if you have only a
>> single
>> > H745; see the second paragraph on page 6-18 of DEC-11-H40SA-B-D.)
>> >
>>
>> I totally missed that. It wasn't in the previous edition,
>> DEC-11-H40SA-A-D.
>>
>> However, now I see that both editions mention that the H744 in slot C is
>> optional, which I also was not previously aware of.
>>
>> Although I've had a few 11/40 machines, I didn't often have to do anything
>> about the power supplies other than check the DC voltage and ripple.
>>
>
>


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