The board was roughly equivalent to the
IMSAI PIO board. However in the case of
this board each line could be separately configured as input or output. The
board required 16 I/O ports to be addressed
via wire jumpers.
IO was
via 1,2 3 or 4 6820 chips. Interrupts could also be
triggered using again wire jumpers. Programming the board was
essentially an effort in programming a 6820.
The manual for this board can be
obtained
here.