Sprite Attribute 2 (with INC) Register

Number	TBRegisterNumber::$77
Readable	TBRegisterReadable::No
Writable	TBRegisterWritable::Yes
Short Description	[[ShortDesc::Same as {{#ask: TBRegisterNumber::$37 }} ($37) (write third byte of sprite-attributes), plus increments {{#ask: TBRegisterNumber::$34 }} ($34)]]

Byte 3 is bitmapped:

Bit	Description
4-7	Palette offset, added to each palette index from pattern before drawing
3	Enable X mirror
2	Enable Y mirror
1	Enable rotation
0	anchor sprite: MSB of X coordinate relative sprite: enable relative Palette offset (1 = the anchor Palette offset is added, 0 = independent Palette offset)

After write into sprite-attribute "byte 3" ({{#ask: PortNumber::$xx57 }} ($xx57{{#ask: PortNumber::$xx57 |mainlabel=- |headers=hide |intro= /  |?NumberDec#- }})), the {{#ask: TBRegisterNumber::$34 }} ($34) is incremented (with all consequences stemming from such action). If the sprite 127 was modified, the result of the increment is officially "undefined behaviour", and code should explicitly set valid 0..127 sprite index before next sprite-attribute manipulation.