Posted By
Luca
on 2007-06-06
16:17:32
 |  Re: Zeropage's addresses emulation
Eh I would, believe me. I can only tell the story as is.
That's happened when I watched my stuff on the real iron: it was perfect on YAPE, but my 3x3 chars text displayer didn't work on the real machine. "Weird", I thought. I tried on VICE and it reproduced the same bug as on real iron.
The reason was this: though I didn't use rom calls and I initialized zeropages loading zeroes from $02 to $FF, the zeropage address'behaviour I used for the 3x3 chars'gfx displayer, changed at a certain point, dunno why. It was $B4, and I has been forced to change it, because whatever I load into it, the result was #$D3 both on real iron and VICE.
The same happened using $90 and $91, used to display 2x2 chars: YAPE has shown to me only ONE bad gfx, where VICE has shown me BOTH, puking random gfx instead of keeping their zero values until I decide to display something (increasing that zero value).
My idea is that zeropages addresses mutually affect themselves: changing a certain address will affect other zp locations. That way, I can find a reason why, i.e., $B4 began to act weird...
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