MSV11-C MOS memory
The MSV11-C (M7955) was a quad-height QBUS DRAM main memory card, introduced in 1975. They held 32KB when fully populated with 4Kx1 DRAM chips, in 4 8KB banks; several partially-populated variants were also available:
- MSV11-CA - 8-Kbyte (M7955-YA)
- MSV11-CB - 16-Kbyte (M7955-YB)
- MSV11-CC - 24-Kbyte (M7955-YC)
- MSV11-CD - 32-Kbyte (M7955-YD)
They provided internal memory refresh, instead of requiring that it be performed externally, by the LSI-11 CPU, like the preceding MSV11-B MOS memory (although the MSV11-C can be configured with on-board jumpers to use external refresh).