Identifying colour attributes with negative numbers

[CharlieJV]

Oops, I thought that was something that worked with anything related to colours.

That works for the colour attribute specified in PSET, but not with the COLOR statement.

Sample code:

Code: (Select All)

1 SCREEN 13
2 DEFINT A-Z
3 L = (L + 1) AND 255
4 PALETTE L, (255 - L) \ 4
5 IF L = 0 THEN GOTO 6 ELSE GOTO 3
6 FOR ix = 1 TO 399
7 FOR iy = 1 TO 199
8 PSET (ix, iy), ((ix - L) XOR (iy + L)) XOR ((ix + L) XOR (iy - L))
' in the PSET statement above, the formula for the colour parameter does return negative values
9 NEXT iy, ix
10 L = (L + 1) AND 255
11 IF INKEY$ <> "" THEN SCREEN 0 ELSE GOTO 6