MM11-K core memory: Difference between revisions
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[[Image:MM11-L_G231.jpg|thumb|300px|right|G231 driver logic board]] | |||
'''MM11-K core memory''' is a rare [[UNIBUS]] [[main memory]] system which is effectively an earlier, smaller version of the common [[MM11-L core memory]]. | '''MM11-K core memory''' is a rare [[UNIBUS]] [[main memory]] system which is effectively an earlier, smaller version of the common [[MM11-L core memory]]. | ||
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The MM11-K also includes an 8 Kbyte H213 quad-format [[core memory]] stack card, instead of the 16 Kbyte H214 card of the MM11-L. It uses all the same custom [[backplane]]s as the MM11-L. | The MM11-K also includes an 8 Kbyte H213 quad-format [[core memory]] stack card, instead of the 16 Kbyte H214 card of the MM11-L. It uses all the same custom [[backplane]]s as the MM11-L. | ||
[[Image:H213-core-memory-board.jpg|thumb|250px|right|H213 core memoryboard]] | |||
On the G110 module, two jumpers (W9 and W10) are set depending on whether it is being used with a 8 Kbyte or a 16 Kbyte core stack; for the MM11-K, W9 is installed, and W10 is removed. On the G231 module, two other jumpers (J3 and J4) are similarly set depending on the size; for the MM11-K, J3 is in, and J4 is out. | On the G110 module, two jumpers (W9 and W10) are set depending on whether it is being used with a 8 Kbyte or a 16 Kbyte core stack; for the MM11-K, W9 is installed, and W10 is removed. On the G231 module, two other jumpers (J3 and J4) are similarly set depending on the size; for the MM11-K, J3 is in, and J4 is out. | ||
Revision as of 15:43, 22 October 2020
MM11-K core memory is a rare UNIBUS main memory system which is effectively an earlier, smaller version of the common MM11-L core memory.
Like the MM11-L, it consists of three cards, two of them the same as those of the MM11-L:
- G110 - hex-format memory control logic and data channels
- G231 - hex-format memory driver logic
The MM11-K also includes an 8 Kbyte H213 quad-format core memory stack card, instead of the 16 Kbyte H214 card of the MM11-L. It uses all the same custom backplanes as the MM11-L.
On the G110 module, two jumpers (W9 and W10) are set depending on whether it is being used with a 8 Kbyte or a 16 Kbyte core stack; for the MM11-K, W9 is installed, and W10 is removed. On the G231 module, two other jumpers (J3 and J4) are similarly set depending on the size; for the MM11-K, J3 is in, and J4 is out.
The effect of these jumpers is to send bus address line A13 to the 'device selector' circuitry, along with A14-A17, in the MM11-K (it goes to 'Decode X-switches', along with A10-A12, in the MM11-L).
Documentation
MM11-K documentation does not appear to be extant; it is covered in the "PDP-11/05 Technical Manual" (EK-11005-TM-003), Chapter 12, "MM11-K and L Detailed Descriptions"; and other MM11-L documentation is of course largely applicable.
