At 05:35 PM 5/7/98 -0400, you wrote:
>So after looking at this I decided to code up the Supercharger support
>so that it pokes 5 memory ACCESSES after an access to f000 to f0ff.
>To my surprise all of the Starpath games worked :-) Now, I guess it
>could be that these games only use the first two code sequences to write
>to RAM or it could be that this is the way the Supercharger really works.
>I also fix a bug in the Supercharger emulation so that Bob Colbert's
>Stell-a-Sketch and Multi game work. I wasn't poking on writes only
>on reads :-)
My theory on the Supercharger hardware is that when the SC is
write-enabled an access to page $f0 triggers a timer that sets the read/write
line on the SC RAM to write for a short period of time while putting the
low-byte of the address in an internal register. It takes a couple of
cycles for the read/write line to go high, and if an address is accessed
within that period of time then the value is stored. I believe there is a
small window of 2 or 3 cycles for which the write would be enabled. I used
the sta instruction because it's more logical when reading the code. I
would guess that other instructions should work too, like inc, dec, eor,
etc...
Great work btw! When can we download the new version?
Later,
Bob
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