Manuel wrote:
> I'd be interested to see if someone has an idea for
> drawing 4 scannline tall missiles even faster than this:
>
> LDX #$1F
> TXS
> LAX scannline
> SBC torpedoyPos ; Torpedo 1
> AND #$FC
> PHP
> TXA
> SBC torpedoyPos+1 ; Torpedo 2
> AND #$FC
> PHP
> DEC scannline
>
> This should be 30 cycles.
If you don't care for the carry this looks good. If you use the
same PHP trick more than once in a kernel, you can reuse the
TXS value directly after the last push (though the LAX/TXA
code doesn't work then anymore).
Anyway, how about this one:
lda #4
dcp torpedoyPos
adc #1
sta ENAM1
lda #4
dcp torpedoyPos+1
adc #1
sta ENAM0
24 cycles! :-)
Have?fun!
Thomas
_______________________________________________________
Thomas?Jentzsch?????????|?***?Every?bit?is?sacred?!?***
tjentzsch?at?web?dot?de?|
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