Difference between revisions of "Enhanced ULA Control Register"

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m (Mikecad moved page ULANext Control Register to Enhanced ULA Control Register without leaving a redirect: ULANext is deprecated)
(Clarified the difference between bits 6:4 and 3:1.)
 
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| 1 || Select ULA palette (0 = first palette, 1 = second palette)
 
| 1 || Select ULA palette (0 = first palette, 1 = second palette)
 
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|-
| 0 || Enabe ULANext mode if 1. (0 after a reset)
+
| 0 || Enable ULANext mode if 1. (0 after a reset)
 
|}
 
|}
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n.b. Bits 6-4 select palette for reading or writing whereas bits 3-1 select the palette for the display signal generator.
  
 
Possible bits 6-4 for palette select (bit 6 selects first/second, 5-4 select type):
 
Possible bits 6-4 for palette select (bit 6 selects first/second, 5-4 select type):
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| %111 || Tilemap second palette
 
| %111 || Tilemap second palette
 
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|}
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Write will also reset the index of {{NextRegNo|$44}}, so the next write there will be considered as first byte of colour.

Latest revision as of 20:13, 31 December 2020

Number $43
Readable Yes
Writable Yes
Short Description Enables or disables Enhanced ULA interpretation of attribute values and toggles active palette.
Bit Function
7 1 to disable palette index write auto-increment
6-4 Select palette for reading or writing
3 Select Sprites palette (0 = first palette, 1 = second palette)
2 Select Layer 2 palette (0 = first palette, 1 = second palette)
1 Select ULA palette (0 = first palette, 1 = second palette)
0 Enable ULANext mode if 1. (0 after a reset)

n.b. Bits 6-4 select palette for reading or writing whereas bits 3-1 select the palette for the display signal generator.

Possible bits 6-4 for palette select (bit 6 selects first/second, 5-4 select type):

Bits 6-4 selects
%000 ULA first palette
%100 ULA second palette
%001 Layer 2 first palette
%101 Layer 2 second palette
%010 Sprites first palette
%110 Sprites second palette
%011 Tilemap first palette
%111 Tilemap second palette

Write will also reset the index of Enhanced ULA Palette Extension ($44), so the next write there will be considered as first byte of colour.