U2
Sega 315-5124
VDP
Video Display Processor
About this component
The VDP generates the whole picture: tiles, sprites and a 64-colour palette at 256x192, using two 8-bit SRAMs (16 KB VRAM) to give it a 16-bit-wide video memory path. It also contains the console's PSG sound generator, so there is no separate sound chip on the board. A dead VDP shows as no picture and no sound together. It is a Sega custom part with no public datasheet; replacements must come from donor boards. Part variants: Model 1 Master System and Mark III boards use 315-5124 (also marked Yamaha YM2602). Master System II boards use the revised 315-5246 (some marked NEC uPD9004G).
What it does on this board
TMS9918-derived graphics chip with extended modes.
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.