MSV11-M QBUS memory
The MSV11-M (M7506) is a dual-height QBUS DRAM main memory card. The MSV11-MB (M7506-BA) holds 1 MByte when fully populated with 256K DRAMs chips, the MSV11-MA (M7506-AA) is half-populated (the only partially-filled configuration allowed) and holds 512 Kbytes.
No documentation on the MSV11-M is extant, so it is currently not known how to configure it. The purpose of the two-position jumper between E19 (apparently a delay line) and E18 is currently unknown.
Each board has a single control register, which can be configured in the range 17772100-17772136, using the set of four jumpers between chips E27 and E26. They are not numbered on the board; for our purposes we will number them W1-W4, starting with the left-hand jumper, with the board oriented with the insertion handles at the top.
As far as is known, there are no copies of the engineering drawings extant for the MSV11-M.
- MSV11-M User Guide (EK-MSV1M-UG - not online)
- MSV11-M Field Maintenance Print Set (MP02053 - not online)