MSV11-R memory module

MSV11-R card

The MSV11-R (M7458) is a quad-height QBUS DRAM main memory card. The MSV111-RA (M7358-A) holds 1 MByte when fully populated with 256K DRAMs chips.

The memory is arranged as 2 banks, each 16 data bits (1 PDP-11 word) wide, with 2 additional bits for parity (1 per byte). It is a Q22 card; reportedly it is also a PMI card.

Configuration

A single 8-position DIP switch configures the card:

• Switches S1-S2 select the 22-bit starting address;
• Switches S3-S4 must always be OFF;
• Switches S5-S8 select the CSR address.

S1	S2	Staring Address
OFF	OFF	00000000 (0 MB)
OFF	ON	04000000 (1 MB)
ON	OFF	10000000 (2 MB)
ON	ON	14000000 (3 MB)

Control Register

Each board has a single control register, which can be configured in the range 17772100-17772136.

S5	S6	S7	S8	CSR Address
ON	ON	ON	ON	17772100
ON	ON	ON	OFF	17772102
ON	ON	OFF	ON	17772104
ON	ON	OFF	OFF	17772106
ON	OFF	ON	ON	17772110
ON	OFF	ON	OFF	17772112
ON	OFF	OFF	ON	17772114
ON	OFF	OFF	OFF	17772116
OFF	ON	ON	ON	17772120
OFF	ON	ON	OFF	17772122
OFF	ON	OFF	ON	17772124
OFF	ON	OFF	OFF	17772126
OFF	OFF	ON	ON	17772130
OFF	OFF	ON	OFF	17772132
OFF	OFF	OFF	ON	17772134
OFF	OFF	OFF	OFF	17772136

Technical information

As far as is known, there are no copies of the engineering drawings extant for the MSV11-R. The following 256K DRAM chips have been observed to be used: MB81256-15 (Fujitsu).

Further reading

• MSV11-R User Guide, EK-MSV1R-UG