ZX Spectrum Sound: From Beeper to AY-3-8910
ZX Spectrum System Tour: Sound
The ZX Spectrum's sound capabilities are explored, covering the 1-bit beeper and the AY-3-8910 chip. The article details using the ROM's BEEPER routine for precise tones, then implementing a custom oscillator with cycle-exact timing, overcoming memory wait states by relocating code and using a global variable. It concludes with a program that plays a C-major scale.
The problem, as it turns out, is that the Spectrum’s video circuitry needs to fetch pixel and color data from the RAM, and it can force the CPU to wait while it does those things.
- moomin
This massively understates what you could do with the basic 1-bit arrangement. People managed to get music playing during gameplay (I think Manic Miner was first) and even managed to play music with two channels and percussion (Robin of the Wood IIRC).
- Razengan
The Spectrum, along with the C64, NES, SNES, etc is still on my to-do list of catching up with computing/gaming history by devving some games for the platforms that started it all ;")