|Old computer veteran from November 1977,|
showing a few front-panel modifications.
- 0000-7FFF - available for RAM (32 KB)
- 8000-9FFF - 32 bytes for the 8 I/O slots (4 bytes per slot) repeated
- A000-BFFF - 128 bytes of ram repeated
- C000-DFFF - available for RAM (8 KB)
- E000-FFFF - 512 bytes of MIKBUG ROM repeated
- MP-B Motherboard
- MP-P Power Supply
- MP-A CPU Board
- MP-M + MP-MX 4K Memory Board
- MP-C Console Serial Port Board
- Metal chassis and case to house the computer
|MP-A CPU board|
MP-M / MP-MX
|MP-M 4KB memory|
A few weeks later, I built the third MP-M/MP-MX, using 2102 chips I ordered by phone. It was cheaper, but not by a lot. There were a few other components for the MP-MX I either obtained from my junk box, or bought locally. You can tell that board by the yellow disc ceramic 0.01 uF capacitors.
You'll note most of the integrated circuits in the SWTPc kits are not socketed. Sockets were considered optional for most components. The MP-A board has sockets for four chips: MC6800, MC6810, MC6830 (MIKBUG), MC14411. The MP-C board has a socket for one chip: MC6820. There were no sockets supplied for the MP-B or MP-M/MX boards. Some builders opted to supply their own.
On the original kits, the back panel had four large holes which passed all I/O cables. In later units, SWTPc added punch-outs for DB-25 connectors for serial devices. Mine has four punch-outs arranged in two horizontal groups just inside the two outermost holes. Other units have four punch-outs in a line above the holes. Other builders have modified their back panels to add other connector types.