>Many games produced by other companies also do color cycling. This
>includes Activision games, and even the Supercharger load screen, though
>the threshold where the color cycling begins is usually a lot longer than
>Atari cartridges.
I'm betting it's double in Activision carts. I went through my printout of
the disassembled Adventure ROM, and found out that it uses two 8-bit
counters, and it alters the colors when bit 7 of the high counter is set.
So the total count to set that bit is 32,768. This is incremented once per
frame, whereone frame is .01666 seconds, so this means the screen will
change approx every 9.1 minutes, if idle. I suppose it could also be done
when the high counter overflows, which would double your time to 18.2
minutes. Anyone ever timed the delay to verify?
-John K. Harvey
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