Posted By
Csabo
on 2003-02-12
|  Re: TAP
That sure is interesting!
For those who didn't know: The bug is caused by $FF13: this TED register specifies the location of the character memory. In the C16 version it's set to $FD, which would be $F800. On the C16 that 16K of memory is mapped to each 16K segment, so it's actually $3800. On a 64K machine this *really* points to $F800, which is uninitialized. Anyway...
The two TAP versions have a different Basic line 20:
C16 version: POKE 65298, PEEK ( 55298 ) OR 2 : POKE 65299, 48
64K version: POKE 65298, 2 : POKE 65299, 56
That 55298 is not a typo. Why is it like that? Incorrectly recorded TAP file? YAPE made an error during loading? An actual bug? It's the same thing with the title screen, the 64K version on our site displays "TOUT", while the C16 version correctly displays "SOUT". From S to T is just one BIT difference (also from 5 to 6, one single bit).
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