The only description of the effects of "program reset" in the original MOS
datasheet is in the section for each register. The W65C51S and W65C51N
datasheets have a heading "PROGRAM RESET OPERATION", but it amounts to:
- internal registers are modified as described in the section for each register
- changes to the DTR, DCD, and DSR pins which Symon does not emulate
- the overrun flag is cleared
...which is what this new implementation does.
It would make *sense* for the reset to do things like "cancel transmission or
reception in progress" and stop asserting an interrupt, as the old code did,
but I can't find any evidence of such behaviour in the datasheets.
Tim Allen
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