Mouse Pissed! Need power supply help - test-drb@ccmp.vtda.org

23 Nov 2005

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Subject: RE: Mouse Pissed! Need power supply help
   From: "Julian Wolfe" <fireflyst at earthlink.net>
   Date: Wed, 23 Nov 2005 13:18:02 -0600
     To: "'General Discussion: On-Topic and Off-Topic Posts'"	<cctalk
at classiccmp.org>

Interesting, I was never aware that the 11/03 and 23 had different boxen
than the 11/23plus, though I knew the power supplies were different.
Speaking to my local DEC salvage dealer, he told me he used to get whole
11/780s just for the power supplies in the front end 11/03s.  However,
judging from the number of 23plus systems that were sold (and have recently
hit, if not flooded, the used market)I'd say it should be fairly easy to
find a cheap H7861 supply. 
There were four major boxes used, and a few oddballs as well.

The majors were:
BA11-m with the H780 on the side. smaller cage.
BA11-N H786 in the front 
BA11-S H7861 in the front

A good PC power supply will do the DC needs of a modest system
but the signals BDCok, BPok, Bhalt, Bevent (ltc), Srun need 
to be created.

Allison

...

  -----Original Message-----
 From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
 On Behalf Of Pete Turnbull
 Sent: Wednesday, November 23, 2005 11:52 AM
 To: General Discussion: On-Topic and Off-Topic Posts
 Subject: Re: Mouse Pissed! Need power supply help

 On Nov 23 2005, 10:51, Charles wrote:
  I've found the reason why my PDP-11 power
supply (H7861) is not
 putting out POK and DCOK signals.  [ ... ]
  Unfortunately the H780 schematic does not match
closely (they use
 74123's while this one uses 555's, for example) so it'll be hard
 to figure out the missing or unreadable parts anyway!  
 The H7861 is a reworked version of the H786 design, which is fairly
 different from the H780.  The H786 is used in the BA11-N box commonly
 used for PDP-11/03 and 11/23 systems, and the H7861 is used in the
 BA11-S box commonly used for 11/23plus and 11/73S systems, so you
 should be able to find the schemeatics amongst the BA11-{N,S} drawings.

 --
 Pete						Peter Turnbull
 						Network Manager
 						University of York 