RL01 drive select plug and power supply questions

[David Betz]

Thanks for your reply. I guess I'm okay with power even if I leave in  
the DHV11 as it seems my BA11-N has been upgraded to a H7861 power  
supply already. I'll consider getting an RQDX3 instead of the RQDX1.  
Do you know if it uses the same cables to connect it with its drives?  
Actually, the only cable I have is to connect the RQDX1 to an RX50  
floppy drive. I'll need a cable to connect it to a hard drive at some  
point. It seems that the RQDX3 cards are easier to come by than the  
cables. I've seen many cards on eBay but never any cables.

On Oct 20, 2005, at 6:19 PM, Allison wrote:

>>
>> 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?
>>
>> Thanks,
>> David
>>
>
> 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.
>
>
> Allison
>