Marinchip Systems developed a CPU board which allowed the Texas Instruments
TMS-9900 processor to be used on the S-1OO bus. This board they
clamed, with its M9900 CPU, replaced the 8080 or Z-8O CPU board in an S-1OO
system, and uses the bus existing memory and peripherals, (or almost any
S-100 compatible board). In other words it acted as an S-100 bus master.
The TMS9900 was an extremely powerful processor, which featured hardware
multiply and divide instructions, multiple sets of 16 general purpose
registers, addressing modes including direct, indirect, indexed, and
auto-increment, and a context switch mechanism that allows both rapid
interrupt response and user extension of the hardware instruction set. The
TMS9900 was a single chip processor that was comparable to the PDP-11 in
many respects, and exceeded it in several important ways, notably the
provision of 16 registers instead of 8 and the fact that the user could have
as many independent register sets as one wanted. The need not be
limited to hardware registers within the CPU.
The manual for this board can be obtained
here and
here.
