Original SWTPC 4K Board
This reproduction board is intended for use in an authentic restoration of an SWTPC computer. For general use we recommend the PT-SS50-64K memory board. The MP-M is an exact copy with no improvements or updates. If you wish to run FLEX, this board will require modification to provide memory from A000-BFFF, the address where FLEX loads. This modification is detailed in SWTPC documentation. This board without modification can only address memory in the lower 32K of memory on 4K boundarys.
This board when used with 250ns memory will work in a 2MHZ 6800 system.
From a 1976 SWTPC Computer Catalog:
The MP-M memory card is a 5-1/2" x 9" double sided plated thru hole board with a total storage capacity of 4096 words of 8 bit random access memory. The kit, however is supplied with only half (2,048 words) of its 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 the address decoding and data line buffering to handle a total of 32 (1K bit x 1bit) 2102 type static random access memories. All interconnections to the system are made via a 50 pin connector to the motherboard (MP-B). +5 volt power for the board is supplied by a on board regulator with heat sink for each 2,048 words of memory. Current consumption is approximately .75A for every 2,048 words of memory.
Downloads
MP_M Assembly Instructions. PDF
MP_MX_AssemblyInstructions.pdf
Assembled MP-M by special order. Price of the board will be quoted after availability and cost of the memory at time of order. Typically the board will cost around $150.
| MP-M-Bare | MP-M Bare Board | $25 |
| MP-M-ASM | Tested and Assembled MP-M with 4K | Inquire |