CompuPro - 68000 CPU
This is a difficult CompuPro (actually
Viasyn) board to
now find. It was used for the development of CPM-68K software when it was thought
that that was the direction future microcomputer software was going to go in the
Clearly it did not happen. Nevertheless the board is quite something and
worth maintaining. The board was introduced in April 1983.
The board normally ran with an 8 MHZ clock with some 10 MHZ versions.
(Remember the clock in 6800x chips was ~2X the Intel chips). The two empty
sockets could accommodate 2716, 2732 or 2764 EPROMS in a high/low byte
The challenge for Motorola CPU's was there was no separate I/O signals.
CompuPro mapped the 256 I/O ports to addresses FF0000H to FFFFFFH. Only the
lower 8 bits were normally used. One unusual thing about the
board was CompuPro allowed the S-100 master clock signal (#24) to be
disabled by a signal on pin 21. This allowed slower slave processors to run
on the bus at a lower speed. The board also allowed up to 5 wait
states be put on the bus.
The 68000 had a built in seven level priority interrupt structure this made
splicing it to an external interrupt controller on the bus a little tricky.
CompuPro provided a few options on this board.
There was a large empty socket in the center of the board that was used to
add an optional 68451 memory management chip.
The schematic for this board can be obtained
. The technical
manual can be obtained
Other CompuPro S-100 Boards
Interfacer 3 Interfacer 4 Interfacer II
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