Posted By
Csabo
on 2022-08-05
22:52:56
|  Re: Question about the character map
Yes, by default, what you described happens.
This is controlled by bit $80 of $FF07.
$00 (default) = 128 characters + 128 inverted characters
$80 = 256 characters (no inverted ones)
This can be found in the encyclopedia here (buried under $FF07), but it's not very obvious 
The only one thing to note about $FF07 is that bit $40 controls the PAL/NTSC setting, therefore you don't want to overwrite that one bit. Sadly, overwriting that one bit directly causes a ton of programs not not be NTSC compatible :-/
So:
LDA#$88 / STA$FF07 -> bad!
LDA$FF07 ORA#$80 STA$FF07 -> good.
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