Palettes: Difference between revisions

Revision as of 10:34, 10 February 2011

There are 2 banks of 256 palettes of 16 colors available, made of 16bit RGB definitions. Palettes are located at $400000 in the 68k's memory map.

The bank used for video output is set by registers REG_PALBANK1 ($3A000E) and REG_PALBANK0 ($3A001E).

Only one bank can be used at a time. They can be switched by using register ???

Color definition word: D R0 G0 B0 R4 R3 R2 R1 G4 G3 G2 G1 B4 B3 B2 B1

Bit	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
Def	Dark bit	R0	G0	B0	R4	R3	R2	R1	G4	G3	G2	G1	B4	B3	B2	B1

Sprite tiles can use any of the 256 palettes, while fix tiles can only use the 16 firsts.

Max colors on screen without RLI tricks: 256*16=4096 out of 2^16=65536.

Palettes are stored in Palette RAM.

@@ Line 1: / Line 1: @@
-There are 2 banks of 256 palettes of 16 colors made of 16bit RGB definitions available.
+There are 2 banks of 256 palettes of 16 colors available, made of 16bit RGB definitions.
-Palettes are located at $400000 in the 68k's memory map and is 16kB in size.
+Palettes are located at $400000 in the 68k's memory map.
+The bank used for video output is set by registers REG_PALBANK1 ($3A000E) and REG_PALBANK0 ($3A001E).
 Only one bank can be used at a time. They can be switched by using register ???
-Color definition: DrgbRRRRGGGGBBBB, D is the Dark bit. RGB are the MSBs of each components, rgb are the LSBs.
+'''Color definition word''':
+D
+<span style="color:red;">R0</span>
+<span style="color:green;">G0</span>
+<span style="color:blue;">B0</span>
+<span style="color:red;">R4 R3 R2 R1</span>
+<span style="color:green;">G4 G3 G2 G1</span>
+<span style="color:blue;">B4 B3 B2 B1</span>
+{{Template:16BitRegister|[[Dark bit]]|1|R0|1|G0|1|B0|1|R4|1|R3|1|R2|1|R1|1|G4|1|G3|1|G2|1|G1|1|B4|1|B3|1|B2|1|B1|1|}}
 [[Sprites|Sprite]] tiles can use any of the 256 palettes, while [[Fix layer|fix]] tiles can only use the 16 firsts.
-Max colors on screen with [[68k interrupts|RLI]] tricks: 256*16=4096 out of 2^16=65536.
+Max colors on screen without [[68k interrupts|RLI]] tricks: 256*16=4096 out of 2^16=65536.
 Palettes are stored in [[Palette RAM]].
 [[Category:Video system]]