Sound#

The TIA has two independent audio channels — the whole orchestra — each described by three registers: AUDC (waveform), AUDF (pitch), and AUDV (volume). A sound is whatever you make by setting those registers and changing them over time, almost always once per frame. There’s no sample memory and no envelopes; expressiveness is rewriting six registers on a schedule.

The chapter’s recurring theme is scarcity met with ingenuity, sound edition: only two voices, a famously out-of-tune pitch ladder, and yet a library full of memorable music.

  • The Audio Registers — the two channels, what AUDC/AUDF/AUDV each do, and the signal path.
  • Tones, Noise & Pitch — the AUDC waveform families, and why the AUDF divisor leaves the VCS unable to play in tune.
  • Playing Music — a frame-counted sequencer driving a (note, duration) song table, plus envelopes and sound effects.

The VCS’s pitches are quantized to the AUDF divisors and are famously out of tune. Picking the closest available divisor per note — and sometimes switching AUDC mode — is part of writing music for it. For richer output, the 4-Voice Music Player bypasses the tone generators and drives the volume DAC directly.

Backward Driving & Keyboard Controllers The Audio Registers Forward