Palette Value (8 bit colour) Register: Difference between revisions
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Fixing read/write vs index auto increment description, thanks to Garry help on Facebook to identify the mistake |
m Xalior moved page Palette Value Register to Palette Value (8 bit colour) Register: match formal nextreg.txt name |
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Format is RRRGGGBB - Note the lowest blue bit of colour (ninth bit) will be set to an OR between bit 1 and bit 0. | Format is RRRGGGBB - Note the lowest blue bit of colour (ninth bit) will be set to an OR between bit 1 and bit 0. | ||
After the write, the palette index is auto-incremented to the next index, if the auto-increment is enabled at {{NextRegNo|$43}}. | After the write, the palette index is auto-incremented to the next index, if the auto-increment is enabled at {{NextRegNo|$43}}. And also the index of {{NextRegNo|$44}} is reset, so the next write there will be considered as first byte of colour. | ||
Read does not auto-increment the index, and reads always the top 8 bits of colour from palette, to read the 9th bit of colour, use {{NextRegNo|$44}} in tandem with value from this register. | Read does not auto-increment the index, and reads always the top 8 bits of colour from palette, to read the 9th bit of colour, use {{NextRegNo|$44}} in tandem with value from this register. | ||
The modified palette remains until a Hard Reset. | The modified palette remains until a Hard Reset. | ||
Latest revision as of 10:57, 14 October 2025
| Next Register Number | $41 |
|---|---|
| Readable | Yes |
| Writable | Yes |
| Short Description | Use to set/read 8-bit colours of the ULANext palette. |
Bits 7-0 = Eight bit colour for the palette index selected by the NextReg:$40.
Format is RRRGGGBB - Note the lowest blue bit of colour (ninth bit) will be set to an OR between bit 1 and bit 0.
After the write, the palette index is auto-incremented to the next index, if the auto-increment is enabled at NextReg:$43. And also the index of NextReg:$44 is reset, so the next write there will be considered as first byte of colour.
Read does not auto-increment the index, and reads always the top 8 bits of colour from palette, to read the 9th bit of colour, use NextReg:$44 in tandem with value from this register.
The modified palette remains until a Hard Reset.