MEM11A Unibus Memory

The MEM11A unibus memory board is intended for older (ie non-MUD) unibus systems.  These systems were predominantly core based.  Its form factor (quad sized/SPC) was dictated by the desire to be able to use a memory board in an 11/20 chassis which is extremely difficult to find memory for since the 11/20 chassis cannot take the hex sized cards.

Features:

• Quad sized board
• Fits in any SPC slot
• 32KW to 128KW on a single board
• uses FRAMs to provide non-volatile memory (aka modern equivalent to core)
• starting address can be any 4KW boundary
• faster than core and typical PDP-11 MOS memories