At 06:36 PM 9/10/2001 +1000, you wrote:
Table-lookup, 256 bytes. Index your original value to get the bit-flipped
It wouldn't need 256 bytes because if only 1 bit is set then there can only
be 8 possible values:
00000001
00000010
00000100
00001000
00010000
00100000
01000000
10000000
Would need to index a table containing:
Lookup
%10000000
%01000000
%00100000
%00010000
%00001000
%00000100
%00000010
%00000001
But how do you use a number like that to create an index?
Would you left shift the accumulator and test for zero and increment the X
register until it reaches zero, then LDA Lookup,X?
To be more specific, I'm starting to think (getting ahead of myself, before
I even have a working kernel) of how to translate an X/Y coordinate of a
collision into a playfield bitmap RAM write. Because the playfield
registers are stored in alternating normal and reversed bit order I can't
just write directly. I need to potentially reverse the bit order before I
OR it with the proper RAM location.
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