MM11-K core memory: Difference between revisions

From Computer History Wiki
Jump to navigationJump to search
extend slightly
Add jumper details and function
Line 8: Line 8:
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.


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; on the G231 module, two other jumpers (J3 and J4) are similarly set depending on the size.
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==
==Documentation==

Revision as of 00:03, 23 February 2018

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 the MM11-L documentation is of course largely applicable.

See also