MP-A2 Microprocessor / System Board

The MP-A2 board is the primary logic board for the SWTPC 6800 Computer
system. It is a 5 1/2 inch x 9 inch circuit board containing the 6800
microprocessor chip, the 6830 ROM which stores the Mini-Operating system and the
6810 128 byte scratch pad memory for the ROM. There is a crystal controlled baud
rate generator providing serial interface baud rates of 110, 150, 300, 600 and
1200 baud. The board also contains a power up/manual reset circuit, which loads
the ROM stored operating system when activated. Full I/O buffering is provided
for the 16 address lines and 8 bi-directional data lines with these and other
inter-connections made to the rest of the system thru a fifty-pin connector to
the mother board (MP-B).

The new MP-A2 board superceded the MP-A board originally provided with the
SWTPC 6800 Computer System and comes equipped with the following features:

Socket provisions for up to 8K of Intel 2716 pinout EPROM, PROM or ROM

Relocatable EPROM/PROM addressing for custom monitor or dedicated
controller applications.
SWTBUG or MIKBUG compatible-switch configurable

Introduced by Southwest Technical Products Corporation in early 1978 and the
MP-A2 kit cost $145.

Board Photo
(59K JPG)

Board Photo High
Resolution (215K JPG)

Assembly
Instructions (115K PDF)

System
Checkout (68K PDF)

Modifying the
MP-A2 for 8K of RAM (170K PDF)

SWTBUG
Users Guide (245K PDF)

Schematic
(314K JPG)

MC6875 Data
Sheet

Michael
Holley's SWTPC Collection Home Page