MS11-K MOS memory: Difference between revisions

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The '''MS11-K MOS memory''' modules were the first generation of memory array modules used in the [[MK11 memory system]] for the [[PDP-11/70]].
The '''MS11-K MOS memory''' modules were the first generation of memory array modules used in the [[MK11 memory system]] for the [[PDP-11/70]]. (The functional difference between the 256KB version of the KS11-K, and the later M8728, is currently unknown.)


[[Image:MS11-KE.jpg|thumb|200px|right|MS11-KE 64KB module]]
[[Image:MS11-KE.jpg|thumb|200px|right|MS11-KE 64KB module]]


Each MS11-K module was a [[DEC card form factor|hex]] board, the M7984. Fully populated, the board holds a total of 156 [[Dynamic RAM|DRAM]] [[integrated circuit|chips]], including 28 to hold the [[Error-correcting code|ECC]]. According to the prints, it could be used with 4Kx1 chips, giving 64KB total storage; or 16Kx1.  
Each MS11-K module was a [[DEC card form factor|hex]] board, the M7984. Fully populated, the board holds a total of 156 [[Dynamic RAM|DRAM]] [[integrated circuit|chips]], including 28 to hold the [[Error-correcting code|ECC]]. According to the prints, it could be used with 4Kx1 chips, giving 64KB total storage; or 16Kx1, giving 256KB.  


Per the prints, these are the configurations and board types:
Per the prints, these are the configurations and board types:
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(The 'x' in the board number is one of a number of letters, starting with 'A', which indicates the manufacturer of the DRAM chips used.)
(The 'x' in the board number is one of a number of letters, starting with 'A', which indicates the manufacturer of the DRAM chips used.)


It is not clear what the difference is between the -KA and the-KE.
It is not confirmed exactly what the difference is between the -KA and the -KE; the prints show the latter as a replacement for the former, and describe the latter's RAM chips as "fast RAM" (200nsec versus 75nsec).


{{semi-stub}}
{{semi-stub}}


[[Category: DEC Memories]]
[[Category: DEC Memories]]

Revision as of 22:15, 1 March 2021

The MS11-K MOS memory modules were the first generation of memory array modules used in the MK11 memory system for the PDP-11/70. (The functional difference between the 256KB version of the KS11-K, and the later M8728, is currently unknown.)

MS11-KE 64KB module

Each MS11-K module was a hex board, the M7984. Fully populated, the board holds a total of 156 DRAM chips, including 28 to hold the ECC. According to the prints, it could be used with 4Kx1 chips, giving 64KB total storage; or 16Kx1, giving 256KB.

Per the prints, these are the configurations and board types:

Board Model Size Configuration
M7984-Ax MS11-KA 64KB 156 x 4K chips
M7984-Bx MS11-KB 32KB 78 x 4K chips
M7984-Cx MS11-KC 256KB 156 x 16K chips
M7984-Dx MS11-KD 64KB 39 x 16K chips
M7984-Ex MS11-KE 64KB 156 x 4K chips
M7984-Fx MS11-KF 128KB 78 x 16K chips

(The 'x' in the board number is one of a number of letters, starting with 'A', which indicates the manufacturer of the DRAM chips used.)

It is not confirmed exactly what the difference is between the -KA and the -KE; the prints show the latter as a replacement for the former, and describe the latter's RAM chips as "fast RAM" (200nsec versus 75nsec).