[A83] Re: Undocumented opcodes


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[A83] Re: Undocumented opcodes




> Has anyone already used undocumented opcodes in his or 
her program, or 
> are there any worth using?
Well, concerning the ixl/ixh/iyl/iyh instructions, I would 
only use them when I'm really out of registers, because 
they are slower than the normal ones (each takes 9 cycles, 
I guess). They're still better than a memory reference, 
though. The combined shift/set/res instructions are nice, 
but I haven't found them useful so far. Probably if I 
revisited some of my code...

BTW what is "neg" good for when you can use "cpl \ inc a" 
instead? Same size, same clocks...

PG





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