Difference between revisions of "System unit"

From Computer History Wiki
Jump to: navigation, search
m (Proper cat)
m (typo)
(2 intermediate revisions by the same user not shown)
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.)
 
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'.
  
 
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.
  
 
{{semi-stub}}
 
{{semi-stub}}
 +
 +
[[Category: DEC Hardware]]

Revision as of 23:19, 13 January 2022

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

The initial system units were 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.)

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 and 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 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.