??????????????? Just a fun thing to do with the Z80MC and SIO card. With some great detective work from Josh and a little bit of tinkering, I was able to get the SIO connected to a Hayesmodem 300 and to get an
old CP/M program called “MODM221A” running. MODM221A is a derivative of the original MODEM program from Ward Christensen.?
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??????????????? Using this combination, there are a few things to note. First, you have to boot to the monitor and make sure that console input is the bit-banger only, and then load CP/M manually. There’s probably
a way to permanently do this, but it would require modifying the system ROM.?
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Second, since DTR and RTS are used as address bits, the ACE initialization in MODM221 has to disable DTR and RTS (or, if those are needed, then the RAM needs to be reduced to 32K and 5V re-routed to put it in
the right place for the 32K RAM).
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??????????????? I don’t have a BBS setup, but I do have all the parts for it – a computer with a Digi 8-port serial board and an analog telephone switch. So, that will be my next project.
