Z80 Assembly 38: Complex Music with the AY-3-8910 Sound Chip
The Limitation of the Beeper The simple beeper (Part 28) can only play one square wave tone at a time. The AY-3-8910 (or compatible) Programmable Sound Generator is a dedicated chip that provides three independent tone channels, a noise generator, and volume control. Communicating with the AY Chip The AY chip uses a few fixed I/O ports for communication. The Z80 talks to it using a two-step process: Select Register: Write the address (0-15) of the internal register you want to modify. Write Data: Write the actual data value to that register. Generic AY Port Example: ...