Sprite Line Buffer

The Sprite Line Buffer is where sprites are pre-rendered to during hblank before being compositied together with the backgrounds. It is 256 pixels wide, and a total of 2304 bits. Internally, it is composed of two 128x9-bit half-line buffers (1152 bits each): one storing even-numbered pixels and the other odd. For each pixel, each half-line buffer stores:

• four bits of color data
• three bits for palette number
• two priority bits

Each of these half-line buffers are clocked at 10.7 MHz (X1/2 divider) during writes and have their own address lines.

References

• https://forums.nesdev.org/viewtopic.php?p=288520#p288520
• https://board.zsnes.com/phpBB3/viewtopic.php?p=204966#p204966