The board was completely IEEE-696 compatible and provided
64 kilobytes of fast static random access memory on the
bus.
Provision was made for 8 or 16 bit transfers, extended 24 bit addressing, and for
control via the bus phantom line. In addition, a number of features were included
to make the board compatible with systems that were designed before the IEEE-696
standard was developed. These included bank selection and provision for operation
with IMSAI-type front panels. When the bank select option was activated, the
board could be divided into two parts which could reside in two separate banks. The division
of the board could be into two 32K sections or into one 16K section and one 48K
section. Provision was made for DMA override of bank selection if needed. The
board was also compatible with IMSAI-type extended addressing.
The board allowed several different 2K or 4K banks of
memory to be disabled and allowed EPROM (2716's) or RAM chips to exist in
the system. The board normally used M58735P static memory chips (Fulcrum
got a good deal on a bulk purchase of the chips). Presumably the board
would also work with the more common HM6116's as well since they have the
same pin-out.
There appears to be two version of the board. The manuals can be obtained
here and
here.
Bill Machrone compared this board to some others in an article in the
January 1983 issue of Microsystems (Vol 4, #1, p70). It can be seen
here.
