Difference between revisions of "Palette Value Register"
From SpecNext official Wiki
(Fixing read/write vs index auto increment description, thanks to Garry help on Facebook to identify the mistake) |
m (4 revisions imported) |
(No difference)
| |
Revision as of 10:00, 14 April 2019
| 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 Palette Index Register ($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 Enhanced ULA Control Register ($43).
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 Enhanced ULA Palette Extension ($44) in tandem with value from this register.
The modified palette remains until a Hard Reset.