Posted By
IstvanV
on 2011-07-04
06:41:06
|  Re: FLD and $FFFF
Some random ideas:
- use a JMP instruction on the zero page to implement the IRQ routine, this way the $FFFF value can be zero (at the expense of 3 bytes of zero page and 3 cycles in the IRQ routine)
- make the garbage invisible by setting a special graphics mode or palette while the $FFFF would be displayed; if you want to use black as the filler color, then setting both bits 6 and 5 of $FF06 during the FLD will switch to the "invalid", all-black video mode, and once the FLD effect is to be stopped, just write the normal $FF06 value
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