Posted By
Csabo
on 2023-12-16
14:46:20
|  Re: change graphics memory
It's a valid question  To turn on multicolor graphics, you need to set 4 TED registers:
$20 bit of $FF06 has to be set (graphics mode)
$10 bit of $FF07 has to be set (multicolor)
The location of the bitmap can be any address on a $2000 boundary ($0000, $2000, $4000, $6000, etc.) This has to be written to $FF12. See the code below for values.
The location of the color map can be any address on a $0800 boundary. The high byte of this has to be written to $FF14.
Here's an actual working example, which turns on multicolor graphics at $8000, with the color map at $7800 (default Multi Botticelli file location):
lda #$3B ; turn graphics mode on
sta $FF06
;
lda $FF07 ; PAL/NTSC friendly
and #$40
ora #$18 ; $18 = multicolor, $08 = hires
sta $FF07
;
lda $FF12
and #$03 ; keep lowest 2 bits (sound)
ora #($8000) >> 10 ; $08 = $2000, $10 = $4000, etc.
sta $FF12
;
lda #$78 ; color map at $7800
sta $FF14
Hopefully this is clear enough
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