Hi Philip,
It is possible. No wires needed, just plug in the module. I developed
a board for a client that has this much functionality on it and it is
small enough that the user wears it under their foot (along with a big
battery and charger coil). The solution I am thinking about would use
0.4mm CSP (Chip Scale Package) type devices that are 7x7mm, 8x8mm, etc.
The way it would achive this with no wires soldered is that the
low-power FPGA would use edges on the ALE pin to detect the timing of
the bus. Then it would monitor the AD0-7 / ALE traffic and "track" the
CPU's instruction flow. This is a simple lookup table of the number of
bytes fetched per instruction. Then for any instruction where the
processor is performing a WRITE or OUT operation while the OptROM CS is
active, the FPGA will fill-in the missing WR signal. It would respond
to I/O requests in the 0x30-0x3F range to provide a type of disk I/O
functionality. At least this is my idea.
This is a board I have wanted to develop for a long time (independent of
M100 use) as a general purpose FPGA + microcontroller board. There are
a lot of FPGA boards on the market, but none that really have what I
want and all of them are for evaluation, and not really small enough to
be used as a final product. The goal would be to make the module fit in
OptROM form factor with a PCB outline that causes the router to cut
through the 28-pin thru-holes. Then for general purpose, the outline is
a bit bigger and the module plugs into a standard white breadboard. For
general purpose, it could be sold to a MUCH LARGER market, meaning
development cost could be recooped.
I *believe* all of this will fit. The main thing I am trying to figure
out is the WiFi. I believe it can fit also, but that soluion would need
two boards stacked with very low-profile connectors (which I have also
used before). The past couple of years, I have been specializing in
small form factor electronics for a client (under the foot, worn on the
wrist, etc.).
Ken
On 7/11/17 4:07 PM, Philip Avery wrote:
Great Ken.
Changing thread to "CP/M Expander"
Is it really possible to fit all that on OptROM form factor? Would it
need a heap of wires soldered to motherboard?
Philip
On 12/07/2017 7:14 AM, Ken Pettit wrote:
Downloaded the remem.bin file and ran CP/M under VT 1.7 on Linux.
Works great!
Now I just need to get my super-cool OptROM form-factor FPGA +
Microcontroller + SRAM + WiFi + Flash board I want to build done. So
much to do ... so little time.
Ken
On 7/8/17 8:28 PM, John R. Hogerhuis wrote:
Files are hosted.
http://bitchin100.com/files/m10x/mtcpm/remem.bin
http://bitchin100.com/files/m10x/mtcpm/Instructions%20for%20M100%20CPM%20v1.0.pdf
I just need to make a page for it or replace the contents of the
MTCPM wiki page.
-- John.
