Re[2]: [cc65] C64 graphic formats and so on

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From: groepaz (groepaz_at_gmx.net)
Date: 2002-05-28 16:38:01 

Hello Stephan,

SL> There are some ram areas which are unusable for graphics data:
SL> 0000-01ff processor port, zero page and stack
SL> 1000-1fff in this area, the video chip doesn't access the ram, but the 
SL>           character rom, which means it can't display graphics data from here
SL> 9000-9fff ditto (or was that d000-dfff? Groepaz?)

$1000 and $9000 are the ROM-images, thats correct..... some additions
to your excerpt though

- the VIC always reads from the colorram at $d800, no matter if the
i/o area is banked in our not (you just cant write to it by means of
the cpu this way but thats another thing ;o))
- same for memory under ROM (a000-bfff and e000-ffff) and memory under
i/o (d000-dfff) ... the VIC always reads from the respective ram, no
matter what the current banking is.

-- 
Best regards,
 groepaz                            mailto:groepaz_at_gmx.net


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