AY‐3‐8910
The AY-3-8910 is a 3-voice programmable sound generator (PSG) designed by General Instrument (GI) in 1978.
The AY-3-8910 and its variants were used in many arcade games, pinball machines, video game consoles and home computers.
The AY-3-8910 is a simple finite-state machine. Its state of sixteen 8-bit registers are programmed over an 8-bit bus (used both for addressing and data) by toggling one of the external pins. For instance, a typical setup cycle puts the bus into "address mode" to select a register, and then switches to "data mode" to set the contents of that register.
The register array is shown below.
| Register | Function |
|---|---|
| 0x00~0x01 | frequency channel 1 |
| 0x02~0x03 | frequency channel 2 |
| 0x04~0x05 | frequency channel 3 |
| 0x06 | noise frequency |
| 0x07 | mixer |
| 0x08 | volume channel 1 |
| 0x09 | volume channel 2 |
| 0x0A | volume channel 3 |