U3
SN76489
Sound
Sound generator
About this component
The Master System's sound comes from a slightly modified copy of the TI SN76489 PSG that lives inside the 315-5124 / 315-5246 VDP. It provides three square-wave channels and one noise channel. There is no separate sound IC to replace, so audio faults are usually in the output and amplifier path or in the VDP itself. Japanese Master Systems additionally carry a Yamaha YM2413 FM chip.
What it does on this board
4-channel PSG audio.
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.