4-color Characters#

The color of each pixel (4 in a line instead of the usual 8) depends on the bit combination of the byte in the character definition.

Bit Pair	Color	Address dec	Address hex	comment
00	COLOR4 BAK	712	$02C8
01	COLOR0 PF0	708	$02C4
10	COLOR1 PF1	709	$02C5
11	COLOR2 PF2	710	$02C6	if bit 7 of character code = 0
11	COLOR3 PF3	711	$02C7	if bit 7 of character code = 1

Example#

character "A" (code=65) would be displayed as

00000000 BAK BAK BAK BAK
00011000 BAK PF0 PF1 BAK
00111100 BAK PF2 PF2 BAK compare with line 3 below
01100110 PF0 PF1 PF0 PF1
01100110 PF0 PF1 PF0 PF1
01111110 PF0 PF2 PF2 PF1 compare with line 6 below
01100110 PF0 PF1 PF0 PF1
00000000 BAK BAK BAK BAK

character "inverse A" (code=193, Bit 7 set because inverse video is on!) would be displayed as

00000000 BAK BAK BAK BAK
00011000 BAK PF0 PF1 BAK
00111100 BAK PF3 PF3 BAK compare with line 3 above
01100110 PF0 PF1 PF0 PF1
01100110 PF0 PF1 PF0 PF1 
01111110 PF0 PF3 PF3 PF0 compare with line 6 above
01100110 PF0 PF1 PF0 PF1
00000000 BAK BAK BAK BAK

To try this, type (works only on an ATARI XL or XE):

GRAPHICS 13:? #6;"A A A":? #6;"A A A":REM the second 3 "A"s are inverse video!

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see also: Color topics, topic list