QBUS memories

QBUS memory cards are available both from DEC, and from a large number of outside vendors who produced and sold QBUS memory cards.

Like the QBUS itself, QBUS memory cards can be divided into Q16, Q18 and Q22 memories. In addition, DEC later specified the PMI memory bus, an extension of the QBUS, and some memory cards have dual QBUS/PMI capability.

Note that although Q18 memory cards can be plugged into a Q22 machine (e.g. most 11/23's, and all 11/73's), and seem to work, they will generally not actually function properly, and will cause subtle errors. This is because a Q18 memory configured for 000000 and up will also respond to bus cycles to 1000000 and up, 2000000 and up, etc. (The sole exception to this rule is in machines with less than 256KB memory, total.)

DEC

Core memory

• MMV11-A - 8-Kbyte unit (H653 and H223)

MOS memory

• MSV11-B - 8-Kbyte (external refresh - M7944)
• MSV11-C - (on-board refresh - M7955)
  • MSV11-CA - 8-Kbyte
  • MSV11-CB - 16-Kbyte
  • MSV11-CC - 24-Kbyte
  • MSV11-CD - 32-Kbyte
• MSV11-D - (no parity - M8044)
  • MSV11-DA - 8-Kbyte
  • MSV11-DB - 16-Kbyte
  • MSV11-DC - 32-Kbyte
  • MSV11-DD - 64-Kbyte
• MSV11-E - (parity - M8045)
  • MSV11-EA - 8-Kbyte
  • MSV11-EB - 16-Kbyte
  • MSV11-EC - 32-Kbyte
  • MSV11-ED - 64-Kbyte
• MSV11-L - (M8059)
  • MSV11-LF - 128-Kbyte
  • MSV11-LK - 256-Kbyte
• MSV11-M - (M7506)
  • MSV11-MA - 512-Kbyte
  • MSV11-MB - 1-Mbyte
• MSV11-P - (M8067)
  • MSV11-PF - 128-Kbyte
  • MSV11-PK - 256-Kbyte
  • MSV11-PL - 512-Kbyte
• MSV11-Q - (M7551)
  • MSV11-QA - 1-Mbyte
  • MSV11-QB - 2-Mbyte
  • MSV11-QC - 4-Mbyte
  • MSV11-SA - 2-Mbyte

PMI MOS memory

• MSV11-J - (M8637)
  • MSV11-JB - 1-Mbyte
  • MSV11-JC - 2-Mbyte
  • MSV11-JD - 1-Mbyte
  • MSV11-JE - 2-Mbyte
• MSV11-R - 1-Mbyte (ECC? - M7458)

Camintonn

• CMV-250 - 256-Kbyte
• CMV-500 - 512-KByte
• CMV-254 - 1-MByte
• CMV-504 - 2-MByte
• CMV-1000 - 1-MByte
• CMV-4000 - 4-MByte

Clearpoint

MOS memory

• Q-RAM 11
  • Q-RAM 11-3 - 256-Kbyte, no parity
  • Q-RAM 11-3 - 256-Kbyte, parity
  • Q-RAM 11-1 - 512-Kbyte, no parity
  • Q-RAM 11 - 512-Kbyte, parity
• Q-RAM 22B
  • Q-RAM 22(B)-3 - 512-Kbyte, no parity
  • Q-RAM 22(B)-3 - 512-Kbyte, parity
  • Q-RAM 22(B)-1 - 1-Mbyte, no parity
  • Q-RAM 22(B) - 1-Mbyte, parity
• Q-RAM 88B
  • Q-RAM 88B-2 - 2-Mbyte
  • Q-RAM 88B - 4-Mbyte
• DCME-Q2A
  • DCME-Q2A/256KB
  • DCME-Q2A/512KB
• DCME-Q2B - 256-Kbyte / 512-Kbyte / 1-Mbyte / 2-Mbyte
  • DCME-Q2B/256KB
  • DCME-Q2B/512KB
  • DCME-Q2B/1MB
  • DCME-Q2B/2MB
• DCME-Q4B
  • DCME-Q4B/512KB
  • DCME-Q4B/1MB
  • DCME-Q4B/2MB
  • DCME-Q4B/4MB

PMI MOS memory

• QED1 (aka QED-F) - 2-Mbyte / 4-Mbyte
• DCME-Q4E - 2-Mbyte / 4-Mbyte

National Semiconductor

• NS23C - 128-Kbyte / 256-KByte / 1-Mbyte, parity
• NS23M - 256-Kbyte, parity
• NS23S - 1-Mbyte, parity