The board could be used with Bank select or extended addressing. The bank
select feature is switch setable to any one of 256 available I/O addresses
and would respond to any one or combination of the eight data bits that are
desired. Extended addressing allowed the MM65K16S to reside anywhere in the
memory map with no imposed limitations by the addressing range of the
microcomputer system.
The board utilized M58725P or equivalent 2KX8 RAM chips. Interestingly you
could pop in 2716 EPROMS as well.
The MM65K16S draws an average of 500 milliamps of current with code
executing in RAM and some boards have measured considerably less under the
same circumstances. With such a low current drain, it is obvious that only 1
regulator was all that was needed, but for those planning to use a
programmed 2716 EPROM or equivalent PROM, extra current demands can easily
be met by the three on board regulators. For those dedicated applications
where both RAM and ROM are needed, the MM65K16S RAM Board really fit the
bill.
The Morrow Designs MM65K16S was guaranteed to run with any 8080, Z80, or
8085 processor on the market at that time. This included some of the new 6
MHZ processors that were beginning to surface. In fact, the MM65K16S was
guaranteed to run reliably with processors that have clock
speeds up to 6 MHZ.
The manual for this board can be
obtained here.
