Difference between pages "Computer operator" and "BA11 mounting boxes"

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A '''computer operator''' usually refers to the person(s) charged with the care and operation of a [[mainframe]] (which were generally so expensive that ordinary [[user]]s were not allowed into their locations).
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The '''BA11''' is the name for a series of [[DEC card form factor|hex]] [[system unit]] [[backplane]] [[mounting box]]es for the [[H960 rack|H960]] series of 19"-wide racks produced by [[Digital Equipment Corporation|DEC]]. Although they were intended to principally be rack-mounted, many were available in table-top configuration as well.
  
Operators would perform tasks such as arranging to run [[job]]s submitted by users, mounting [[magnetic tape]]s and [[disk]] packs, and [[bootstrap]]ping the [[operating system]] after the machine crashed, or was powered on.
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The H960 racks provided 63" of vertical mounting space, divided into units of 10-1/2", which were further sub-dividable into a pair of 5-1/4" spaces. The BA11 mounting boxes were designed for these spaces.
  
Operators were generally not [[programmer]]s, but on a large mainframe they had to know a fair amount - e.g. how to deal with a [[multi-processor]] system which had had one of the [[Central Processing Unit|CPU's]] fail, which would require:
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They included:
  
* recognizing that a CPU failure had occurred
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* [[BA11-A mounting box|BA11-A]] - the terminal letter notwithstanding, a late unit, used for the [[PDP-11/44]]
* working out which CPU had failed
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* BA11-B - mentioned briefly in some early documentation; the details of what it was are still unclear
* reconfiguring the system so that it would not try to use that CPU
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* [[BA11-C Mounting Box|BA11-C]] - the first, used in the [[PDP-11/20]]
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* [[BA11-D Mounting Box|BA11-D]] - used for the [[PDP-11/05]] and early [[PDP-11/40]]'s
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* [[BA11-E Mounting Box|BA11-E]] - expansion box, used with the early [[PDP-11]]s
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* [[BA11-F Mounting Box|BA11-F]] - used in the larger [[UNIBUS]] -11's like the [[PDP-11/45]]
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* [[BA11-K mounting box|BA11-K]] - used to hold both [[Central Processing Unit|CPUs]] as well as [[device controller]]s for UNIBUS -11's
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* [[BA11-L mounting box|BA11-L]] - ditto
  
{{semi-stub}}
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The -F was a 21" box, and the -E and -L were 5-1/4"; the rest were all 10-1/2". All of them other than the earliest -C and -E models provided the standard [[DEC power distribution connectors]]; the 9-[[pin]] version in the -D, and the 6/15 version in the others.
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There were also several boxes in the BA11 series which held [[DEC card form factor|quad]] [[QBUS]] backplanes:
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* [[BA11-M mounting box|BA11-M]]
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* [[BA11-N mounting box|BA11-N]]
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* [[BA11-S mounting box|BA11-S]]
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These were all 5-1/4" high.
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[[Category: DEC Hardware]]

Revision as of 01:42, 7 February 2019

The BA11 is the name for a series of hex system unit backplane mounting boxes for the H960 series of 19"-wide racks produced by DEC. Although they were intended to principally be rack-mounted, many were available in table-top configuration as well.

The H960 racks provided 63" of vertical mounting space, divided into units of 10-1/2", which were further sub-dividable into a pair of 5-1/4" spaces. The BA11 mounting boxes were designed for these spaces.

They included:

The -F was a 21" box, and the -E and -L were 5-1/4"; the rest were all 10-1/2". All of them other than the earliest -C and -E models provided the standard DEC power distribution connectors; the 9-pin version in the -D, and the 6/15 version in the others.

There were also several boxes in the BA11 series which held quad QBUS backplanes:

These were all 5-1/4" high.