RL01 drive select plug and power supply questions

Allison ajp166 at bellatlantic.net
Thu Oct 20 17:19:37 CDT 2005

>Subject: RL01 drive select plug and power supply questions
>   From: David Betz <dbetz at xlisper.mv.com>
>   Date: Thu, 20 Oct 2005 17:28:56 -0400
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>Does anyone have a spare RL01 drive select plug for drive "0"? I
>recently acquired an RL01 drive (thanks Lyle Bickly and Jon Miles!)
>but it's missing its drive select plug. This is one of the four
>lights on the front of the drive that has the number "0" printed on
>it for drive 0. Does anyone have one they're willing to part with?
>Also, the PDP-11/73 that I acquired is in a BA11-NC box. Does anyone
>know how much power the power supply in this box can supply? There is
>a list of the cards in the box and the power each one consumes and
>I've inserted an additional card (an RQDX1 controller) that draws
>6.4A at 5V and I'm not sure that the power supply can handle it. That
>would bring the total to 26.9A at 5V where the original total was
>22.3A. I could remove a DHV11 card that draws 4.3A to bring the total
>down to 22.6A if necessary. What is save with this power supply?

BA-11N +5 at 22A +12 at 11A max  assumes H9273 mackplane and H786 PS

I have a system that I subbed in a H7861 to the BA11N that PS is same size
and form factor but +5 at 36A and +12 at 5A (typically found in BA11S). As most 
newer boards had a greater need for +5 than +12.

If you don't need the serial lines then pull the DHV11.  I've found 
running the supply right at the limit was not the best for reliability.

Also the RQDX1 was not a very good version unless it was upgraded to 
RQDX2.  the reason is it didn't support RX33, and the largest disk 
if memory serves for RQDX1 was RD52 (30mb quantum D540).  RQDX2 supported
the RD53(70mb) and RD54 (150mb).  The RQDX3 supported more drives and
is a bit lighter in current draw (RD31 and 32 plus RX33).

ALSO the RQDX1 MUST BE LAST ON THE BUS.  Many of the RQDX1 controllers 
lacked GRANT pass down.  


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