Difference between revisions of "MSV11-C MOS memory"
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They are [[QBUS#Variable address size|Q18]] cards (hence, could not be used in Q22 systems, such as [[PDP-11/23]]'s with more than 256KB of memory). Their starting [[address]] is configured by use of [[Dual Inline Package|DIP]] switches. | They are [[QBUS#Variable address size|Q18]] cards (hence, could not be used in Q22 systems, such as [[PDP-11/23]]'s with more than 256KB of memory). Their starting [[address]] is configured by use of [[Dual Inline Package|DIP]] switches. | ||
| − | They provided internal [[refresh]], instead of requiring that it be performed externally, by the [[LSI-11]] [[Central Processing Unit|CPU]], like the preceding [[MSV11-B MOS memory]] (although the MSV11-C can be configured with on-board [[jumper]]s to use external refresh). | + | They provided internal [[memory refresh]], instead of requiring that it be performed externally, by the [[LSI-11]] [[Central Processing Unit|CPU]], like the preceding [[MSV11-B MOS memory]] (although the MSV11-C can be configured with on-board [[jumper]]s to use external refresh). |
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==External links== | ==External links== | ||
| + | * [http://www.bitsavers.org/pdf/dec/qbus/Digital_Microcomputer_Processor_Handbook_1979_80.pdf microcomputer processor handbook] - the MSV11-C is covered in Chapter 12, pp. 451-473 (pp. 461-483 of the PDF) | ||
* [http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/EK-MSV11-OP-001%20MSV11-C%20User's%20Manual.pdf MSV11-C user's manual] (EK-MSV11-OP-001) | * [http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/EK-MSV11-OP-001%20MSV11-C%20User's%20Manual.pdf MSV11-C user's manual] (EK-MSV11-OP-001) | ||
* [http://bitsavers.org/pdf/dec/pdp11/1103/1103_Schematics.pdf PDP-11/03 Engineering Drawings] - MSV11-C Field Maintenance Print Set (MP00259) is on pp. 97-126 of the PDF | * [http://bitsavers.org/pdf/dec/pdp11/1103/1103_Schematics.pdf PDP-11/03 Engineering Drawings] - MSV11-C Field Maintenance Print Set (MP00259) is on pp. 97-126 of the PDF | ||
Latest revision as of 19:35, 13 July 2023
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 are Q18 cards (hence, could not be used in Q22 systems, such as PDP-11/23's with more than 256KB of memory). Their starting address is configured by use of DIP switches.
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).
External links
- microcomputer processor handbook - the MSV11-C is covered in Chapter 12, pp. 451-473 (pp. 461-483 of the PDF)
- MSV11-C user's manual (EK-MSV11-OP-001)
- PDP-11/03 Engineering Drawings - MSV11-C Field Maintenance Print Set (MP00259) is on pp. 97-126 of the PDF
- M7955 MSV11-C RAM - board image
