UNIBUS priority plug - Revision history

Jnc: Point out that the plug performed two, matched, functions

2024-02-24T02:43:31Z

Point out that the plug performed two, matched, functions

Vaxorcist: "BR - Bus Request" added

2024-02-23T13:08:46Z

"BR - Bus Request" added

Vaxorcist: Missing part numbers added

2024-02-23T11:28:01Z

Missing part numbers added

Jnc: link BGL

2024-02-22T18:38:54Z

link BGL

Jnc: +part # table

2022-11-07T14:56:21Z

+part # table

Jnc: Relatively complete

2022-11-07T14:47:47Z

Relatively complete

New page

A '''UNIBUS priority plug''' is an insertable plug, physically a [[Dual Inline Package|DIP]], which was inserted into almost all [[UNIBUS]] [[peripheral|devices]] in order to select which daisy-chained [[interrupt]] [[bus grant]] line, of the four such available on the UNIBUS (BG4, BG5, BG6, and BG7), the device's [[Bus Arbitration on the Unibus and QBUS|grant-acquiring/passing circuitry]] was connected to. As a secondary purpose, it passed all the other grant lines past the device.

As part of the configuration of a device being added to a system, it was necessary to ensure that a priority plug for the desired priority level was installed in the device.

Priority plugs were manufactured by [[Digital Equipment Corporation|DEC]] for all four priority levels. Most devices also came with a plug pre-installed at manufacturing time, at a level selected by DEC as likely the most appropriate interrupt priority level for that device; they were rarely changed.

[[Category: UNIBUS]]

@@ Line 1: / Line 1: @@
-A '''UNIBUS priority plug''' is an insertable plug, physically a [[Dual Inline Package|DIP]], which was inserted into almost all [[UNIBUS]] [[peripheral|devices]] in order to select which daisy-chained [[interrupt]] [[bus grant line]], of the four such available on the UNIBUS (BG4, BG5, BG6, and BG7), the device's [[Bus Arbitration on the Unibus and QBUS|grant-acquiring/passing circuitry]] was connected to. As a secondary purpose, it passed all the other grant lines past the device.
+A '''UNIBUS priority plug''' is an insertable plug, physically a [[Dual Inline Package|DIP]], which was inserted into almost all [[UNIBUS]] [[peripheral|devices]] in order to perform two separate functions related to the device being able to perform [[interrupt]]s via the [[bus]]:
-As part of the configuration of a device being added to a system, it was necessary to ensure that a priority plug for the desired priority level was installed in the device.
+* connect the device to the desired [[bus request line]] (the UNIBUS provided 4 different priorities of interrupt, with a request line for each - BR4 through BR7);
-Another name for "priority level" was '''bus request''', usually abbreviated to "'''BR'''"; the manuals usually state e.g. '''BR 5''' for priority level 5.
+* insert the device's [[Bus Arbitration on the Unibus and QBUS|grant-acquiring/passing circuitry]] into the matching daisy-chained [[bus grant line]], of the four such available on the UNIBUS (BG4 through BG7).
-Priority plugs were manufactured by [[Digital Equipment Corporation|DEC]] for all four priority levels:
+(Secondarily to the latter, it passed all the other grant lines past the device.)
 {| class="wikitable"

← Older revision		Revision as of 13:08, 23 February 2024
Line 2:		Line 2:

	As part of the configuration of a device being added to a system, it was necessary to ensure that a priority plug for the desired priority level was installed in the device.		As part of the configuration of a device being added to a system, it was necessary to ensure that a priority plug for the desired priority level was installed in the device.
		+
		+	Another name for "priority level" was '''bus request''', usually abbreviated to "'''BR'''"; the manuals usually state e.g. '''BR 5''' for priority level 5.

	Priority plugs were manufactured by [[Digital Equipment Corporation\|DEC]] for all four priority levels:		Priority plugs were manufactured by [[Digital Equipment Corporation\|DEC]] for all four priority levels:

@@ Line 8: / Line 8: @@
 ! Level !! [[DEC part number]]
 |-
-| 4 || &nbsp;
+| 4 || 54-08776
 |-
 | 5 || 54-08778
 |-
-| 6 || &nbsp;
+| 6 || 54-08780
 |-
-| 7 || &nbsp;
+| 7 || 54-08782
 |}

← Older revision		Revision as of 18:38, 22 February 2024
Line 1:		Line 1:
−	A '''UNIBUS priority plug''' is an insertable plug, physically a [[Dual Inline Package\|DIP]], which was inserted into almost all [[UNIBUS]] [[peripheral\|devices]] in order to select which daisy-chained [[interrupt]] [[bus grant]] ~~line~~, of the four such available on the UNIBUS (BG4, BG5, BG6, and BG7), the device's [[Bus Arbitration on the Unibus and QBUS\|grant-acquiring/passing circuitry]] was connected to. As a secondary purpose, it passed all the other grant lines past the device.	+	A '''UNIBUS priority plug''' is an insertable plug, physically a [[Dual Inline Package\|DIP]], which was inserted into almost all [[UNIBUS]] [[peripheral\|devices]] in order to select which daisy-chained [[interrupt]] [[bus grant line]], of the four such available on the UNIBUS (BG4, BG5, BG6, and BG7), the device's [[Bus Arbitration on the Unibus and QBUS\|grant-acquiring/passing circuitry]] was connected to. As a secondary purpose, it passed all the other grant lines past the device.

	As part of the configuration of a device being added to a system, it was necessary to ensure that a priority plug for the desired priority level was installed in the device.		As part of the configuration of a device being added to a system, it was necessary to ensure that a priority plug for the desired priority level was installed in the device.

@@ Line 3: / Line 3: @@
 As part of the configuration of a device being added to a system, it was necessary to ensure that a priority plug for the desired priority level was installed in the device.
-Priority plugs were manufactured by [[Digital Equipment Corporation|DEC]] for all four priority levels. Most devices also came with a plug pre-installed at manufacturing time, at a level selected by DEC as likely the most appropriate interrupt priority level for that device; they were rarely changed.
+Priority plugs were manufactured by [[Digital Equipment Corporation|DEC]] for all four priority levels:
 [[Category: UNIBUS]]