> However, you can save 1 byte of RAM by using the branch instructions instead, as long as you know which flag(s), if any, are guaranteed to be on or off at the jump point.
> For example, if you know the carry flag will always be clear at the jump point, and if the jump distance is within branching range, you can replace JMP with BCC.
However if the BCC crosses a page boundary it'll take 4 cycles, one cycle longer than a JMP.
diydsp 2 hours ago [-]
Ah so with splites you can have a 24 pix wide column of arbitrary data that can be slid around left to right....and may act as an "echo" of the players movement like in this game...or possibly even different physics...
I love the stacking of boolean ops before branches, too.
> For example, if you know the carry flag will always be clear at the jump point, and if the jump distance is within branching range, you can replace JMP with BCC.
However if the BCC crosses a page boundary it'll take 4 cycles, one cycle longer than a JMP.
I love the stacking of boolean ops before branches, too.