System unit - Revision history

Jnc: Mention used for CPUs

2023-12-23T13:45:11Z

Mention used for CPUs

Jnc: typo

2022-01-13T22:19:28Z

typo

Jnc: A-F 'connectors'

2021-08-02T17:24:24Z

A-F 'connectors'

Jnc: +cat

2018-12-19T23:50:46Z

+cat

Jnc: Proper cat

2018-10-21T13:43:00Z

Proper cat

Jnc: Avoid redirs

2017-10-29T11:57:13Z

Avoid redirs

Jnc: Not bad for a start...

2017-05-07T15:27:09Z

Not bad for a start...

New page

A '''system unit''' is a standard modular [[backplane]] from [[DEC]], used mostly in [[UNIBUS]] [[PDP-11]]s.

The initial system units were [[DEC card form factor|hex]] height, four-slot assemblies. (Sometimes a number of these were wired together to form a single unit, such as in the [[PDP-11/20]]'s [[KA11]] [[CPU]], which used three.)

Late on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], the latter for both the CPU and memories such as the [[MJ11]] and [[MK11]]) which were even wider than that, but generally a double was the maximum width for an option.

All the DEC chassis boxes (such as the [[BA11-K]] and [[BA11-L]]) had mechanical mountings and DC power connectors intended to hold system units.

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@@ Line 3: / Line 3: @@
 The initial system units were [[DEC card form factor|hex]] height, four-slot assemblies. (Sometimes a number of these were wired together to form a single unit, such as in the [[PDP-11/20]]'s [[KA11]] [[Central Processing Unit|CPU]], which used three.)
-Later on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], in the latter backplanes for both the CPU and memories such as the [[MJ11 memory system‎|MJ11]] and [[MK11 memory system‎|MK11]]) which were even wider than that, but generally a double was the maximum width for an option.
+Later on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[Central Processing Unit|CPUs]] of the [[PDP-11/45]] and [[PDP-11/70]]; in the latter backplanes for both the CPU and memories such as the [[MJ11 memory system‎|MJ11]] and [[MK11 memory system‎|MK11]]) which were even wider than that, but generally a double was the maximum width for an option.
 Each slot held six 'connectors', DEC's term for a [[DEC edge connector contact identification|group of edge connector pins]], denominated 'A'-'F'.

@@ Line 3: / Line 3: @@
 The initial system units were [[DEC card form factor|hex]] height, four-slot assemblies. (Sometimes a number of these were wired together to form a single unit, such as in the [[PDP-11/20]]'s [[KA11]] [[Central Processing Unit|CPU]], which used three.)
-Late on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], in the latter backplanes for both the CPU and memories such as the [[MJ11 memory system‎|MJ11]] and [[MK11 memory system‎|MK11]]) which were even wider than that, but generally a double was the maximum width for an option.
+Later on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], in the latter backplanes for both the CPU and memories such as the [[MJ11 memory system‎|MJ11]] and [[MK11 memory system‎|MK11]]) which were even wider than that, but generally a double was the maximum width for an option.
 Each slot held six 'connectors', DEC's term for a [[DEC edge connector contact identification|group of edge connector pins]], denominated 'A'-'F'.

← Older revision		Revision as of 17:24, 2 August 2021
Line 4:		Line 4:

	Late on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], in the latter backplanes for both the CPU and memories such as the [[MJ11 memory system‎\|MJ11]] and [[MK11 memory system‎\|MK11]]) which were even wider than that, but generally a double was the maximum width for an option.		Late on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], in the latter backplanes for both the CPU and memories such as the [[MJ11 memory system‎\|MJ11]] and [[MK11 memory system‎\|MK11]]) which were even wider than that, but generally a double was the maximum width for an option.
		+
		+	Each slot held six 'connectors', DEC's term for a [[DEC edge connector contact identification\|group of edge connector pins]], denominated 'A'-'F'.

	All the DEC chassis boxes (such as the [[BA11-K]] and [[BA11-L]]) had mechanical mountings and DC power connectors intended to hold system units.		All the DEC chassis boxes (such as the [[BA11-K]] and [[BA11-L]]) had mechanical mountings and DC power connectors intended to hold system units.

← Older revision		Revision as of 23:50, 19 December 2018
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	{{semi-stub}}		{{semi-stub}}
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		+	[[Category: DEC Hardware]]

← Older revision		Revision as of 13:43, 21 October 2018
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	All the DEC chassis boxes (such as the [[BA11-K]] and [[BA11-L]]) had mechanical mountings and DC power connectors intended to hold system units.		All the DEC chassis boxes (such as the [[BA11-K]] and [[BA11-L]]) had mechanical mountings and DC power connectors intended to hold system units.

−	{{stub}}	+	{{semi-stub}}

@@ Line 1: / Line 1: @@
-A '''system unit''' is a standard modular [[backplane]] from [[DEC]], used mostly in [[UNIBUS]] [[PDP-11]]s.
+A '''system unit''' is a standard modular [[backplane]] from [[Digital Equipment Corporation|DEC]], used mostly in [[UNIBUS]] [[PDP-11]]s.
-The initial system units were [[DEC card form factor|hex]] height, four-slot assemblies. (Sometimes a number of these were wired together to form a single unit, such as in the [[PDP-11/20]]'s [[KA11]] [[CPU]], which used three.)
+The initial system units were [[DEC card form factor|hex]] height, four-slot assemblies. (Sometimes a number of these were wired together to form a single unit, such as in the [[PDP-11/20]]'s [[KA11]] [[Central Processing Unit|CPU]], which used three.)
-Late on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], the latter for both the CPU and memories such as the [[MJ11]] and [[MK11]]) which were even wider than that, but generally a double was the maximum width for an option.
+Late on, 'double' system units (also hex-height, but nine slots wide) appeared. There were also custom backplanes (such as for the [[PDP-11/45]] and [[PDP-11/70]], in the latter backplanes for both the CPU and memories such as the [[MJ11 memory system‎|MJ11]] and [[MK11 memory system‎|MK11]]) which were even wider than that, but generally a double was the maximum width for an option.
 All the DEC chassis boxes (such as the [[BA11-K]] and [[BA11-L]]) had mechanical mountings and DC power connectors intended to hold system units.
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