Unrecognized DEC Power Supply in PDP-11/44 Configuration

Rick Murphy rick at rickmurphy.net
Fri Dec 3 05:36:27 CST 2021


Those red cables appear to be SDI - maybe that spot was an RA80/RA81?
The boards appear to be correct for a UDA50 (M7485/M7486, but it's hard 
to make out the board numbers).
     -Rick

On 12/2/2021 11:37 AM, Josh Dersch via cctalk wrote:
> On Thu, Dec 2, 2021 at 6:29 AM pbirkel--- via cctalk <cctalk at classiccmp.org>
> wrote:
>
>> Does anyone recognize the (presumably) DEC power supply on the front half
>> of
>> the rack-bottom in the 11/44 listing at:
>>
>>
>>
>> https://www.ebay.com/itm/363640137050
>>
>>
>>
>> Blurry photo, but it looks like there are a 4x3, a 3x3, and a 3x5 Molex
>> connector, and two brown mini-modules protruding from the right side.
>>
>>
>>
>> If so, then what purpose did it likely serve?
>>
> It's not a DEC power supply, it's a Fujitsu power supply, likely for an
> M2284 SMD drive.  Probably went in the empty slot you mention below.
>
> - Josh
>
>
>
>>
>>
>> It appears that the 6U immediately below the 11/44 was likely occupied by
>> an
>> RX02 given the presence of an M8256 in the 11/44 backplane (and skinny
>> mounting rails, although I thought those were usually at the bottom of the
>> RX02), and that included its own power supply (which wasn't very beefy
>> either, nor did it need to be).
>>
>>
>>
>> What went into the 6U immediately above the power supply is unclear; there
>> is a HEX Wespercorp TC130 Tape Controller as well as three unknown QUAD
>> modules in the 11/44 backplane.  Perhaps there was a horizontal autoload
>> tape drive mounted there that required a separate power supply?
>>
>>
>>
>> Curious!
>>
>> paul
>>
>>



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