Difference between revisions of "Palette Value Register"

From SpecNext official Wiki
Jump to: navigation, search
(Rewording a bit and adding info from web docs.)
(Fixing read/write vs index auto increment description, thanks to Garry help on Facebook to identify the mistake)
Line 10: Line 10:
  
 
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}}.
 +
 +
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.

Revision as of 00:31, 7 January 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.