Difference between revisions of "BA11-S mounting box"

From Computer History Wiki
Jump to: navigation, search
m (+cat)
m (avoid redir)
Line 1: Line 1:
 
The '''BA11-S mounting box''' was a [[QBUS]] [[PDP-11]] [[mounting box]] from [[Digital Equipment Corporation|DEC]]; effectively a [[QBUS#Variable_address_size|Q22]] variant of the earlier [[BA11-N mounting box]]. The manual says the BA11-S was for [[PDP-11/23B]].
 
The '''BA11-S mounting box''' was a [[QBUS]] [[PDP-11]] [[mounting box]] from [[Digital Equipment Corporation|DEC]]; effectively a [[QBUS#Variable_address_size|Q22]] variant of the earlier [[BA11-N mounting box]]. The manual says the BA11-S was for [[PDP-11/23B]].
  
It included the up-rated H7861 [[power supply]] (which provided 36A of +5V, and 5A of +12V); and an H9276 9-slot [[QBUS#Backplane|Q22/CD]] [[backplane]], which could hold [[DEC card form factor|quad-sized]] cards.
+
It included the up-rated H7861 [[power supply]] (which provided 36A of +5V, and 5A of +12V); and an H9276 9-slot [[QBUS#Backplanes|Q22/CD]] [[backplane]], which could hold [[DEC card form factor|quad-sized]] cards.
  
Since it was a Q/[[CD interconnect|CD]] backplane, dual-width [[QBUS]] cards could only be placed in the left-hand slots, and quad QBUS-only cards had to not use any pins on the [[DEC edge connector contact identification|right-hand C/D connectors]]. (The only DEC card with a problem with this  seems to have been the [[MMV11-A]].)
+
Since it was a Q/[[CD interconnect|CD]] backplane, dual-width [[QBUS]] cards could only be placed in the left-hand slots, and quad QBUS-only cards had to not use any pins on the [[DEC edge connector contact identification|right-hand C/D connectors]]. (The only DEC card with a problem with this  seems to have been the [[MMV11-A QBUS core memory|MMV11-A]].)
  
 
It was available both with a front panel with a bezel (with '[[Bootstrap|Boot]]', '[[Halt]]' and '[[LTC]] On' switches, and power and run status indicators); and also with a blank front panel (for use as an expansion box).
 
It was available both with a front panel with a bezel (with '[[Bootstrap|Boot]]', '[[Halt]]' and '[[LTC]] On' switches, and power and run status indicators); and also with a blank front panel (for use as an expansion box).

Revision as of 17:57, 16 November 2019

The BA11-S mounting box was a QBUS PDP-11 mounting box from DEC; effectively a Q22 variant of the earlier BA11-N mounting box. The manual says the BA11-S was for PDP-11/23B.

It included the up-rated H7861 power supply (which provided 36A of +5V, and 5A of +12V); and an H9276 9-slot Q22/CD backplane, which could hold quad-sized cards.

Since it was a Q/CD backplane, dual-width QBUS cards could only be placed in the left-hand slots, and quad QBUS-only cards had to not use any pins on the right-hand C/D connectors. (The only DEC card with a problem with this seems to have been the MMV11-A.)

It was available both with a front panel with a bezel (with 'Boot', 'Halt' and 'LTC On' switches, and power and run status indicators); and also with a blank front panel (for use as an expansion box).

It was a 5-1/4" tall mounting box, for the H960 series of 19"-wide racks, one of the BA11 mounting boxes. The H960 racks provided 63" of vertical mounting space, divided into units of 10-1/2", which were further subdividable into a pair of 5-1/4" spaces. The 5-1/4" tall BA11-S mounting box was designed for these spaces.

For rack mounting purposes. it did not use external slides (as all the other BA11 mounting boxes did); instead, it was housed in an external 'skin' (termed a 'logic box cover' in DEC documentation, the base unit being called a 'logic box') into which it is slid; the cover would be bolted to the rack.

The backplane was mounted vertically, facing backward (unlike the BA11-M mounting box, where they had been facing forward). Cooling fans mounted on the side of the BA11-S passed air both over the boards, and through the power supply.

The BA11-S's dimensions were 5-1/4" high, 19" wide, and 22-3/4" deep, and it weighed 44 lbs (without any boards). The rack mounting was 26-3/4" long.