5C77-01 (S-PPU1) + 5C78-03 (S-PPU2)
About this component
Graphics on 3-chip SNES boards are split across two 100-pin QFP chips that share 64 KB of VRAM (two 32 KB chips). PPU1 (5C77) handles tile and sprite fetching and the Mode 7 rotation/scaling, while PPU2 (5C78) does windowing, mosaic, colour maths and feeds the video encoder. Graphical corruption, wrong colours or a black screen can point to these chips or their VRAM, though bad solder joints and the cartridge slot are more common causes. 1CHIP boards drop both chips in favour of the single S-CPUN. Part variants: S-PPU1 is always 5C77-01. S-PPU2 is 5C78-01 on early boards, rare 5C78-02, then 5C78-03. On 1CHIP and SNS-101 boards both PPUs and the CPU are merged into S-CPUN (RF5A122).
Two-chip graphics processor (combined on 1CHIP boards).
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.