MP-M Memory Board
The MP-M Memory Board is a 5 1/2 inch x 9 inch board with a total storage capability of 4,096 words of 8 bit random access memory. The kit, however, is supplied with only half (2,048 words) of it's memory capacity. To bring the board to maximum capacity, you must purchase the MP-MX memory expansion kit. The circuitry on the board provides all of the address decoding and data line buffering to handle a total of 32 (1K bit x 1 bit) 2102 type static random access memories. All interconnections to the system are made via a 50 pin connector to the Mother Board (MP-B). +5 volt power for the board is supplied by a on board regulator with heatsink for each 2,048 words of memory. Current consumption is approximately 0.75 A for every 2,048 words of memory.
The system could have 4 boards for a total of 16K bytes. This drew 6 amps of 5 volts.
Introduced by Southwest Technical Products Corporation in 1975. The MP-M kit cost $80 and the MP-MX cost $45.
Board Photo (80K JPG)
Board Photo High Resolution (300K JPG)
MP-M Assembly Instructions (160K PDF)
MP-MX Assembly Instructions (160K PDF)
Schematic (409K PDF)
The MP-M (and MP-8M) can be modified for operation above 32K. See the MP-A2 Assembly Manual for details (page 9.)
I bought bare boards from SWTPC and parts from James Electronics (now JAMECO) Here is a receipt.
Michael Holley's SWTPC Collection Home Page