4 hours ago
- The ZX Spectrum offers two sound options: a 1-bit beeper and an AY-3-8910 synthesizer chip.
- The 1-bit beeper can be controlled via BIOS routine at $03B5 using frequency and duration codes derived from formulas.
- A direct beeper routine with precise timing avoids branch timing issues using JP instructions instead of JR.
- The direct beeper method suffers from CPU wait states due to video memory access, requiring code relocation or workarounds.