SID MONITOR

VOICE 1 OFF
FREQ
0
ENV
0
A:0 D:0 S:0 R:0
GATE
VOICE 2 OFF
FREQ
0
ENV
0
A:0 D:0 S:0 R:0
GATE
VOICE 3 OFF
FREQ
0
ENV
0
A:0 D:0 S:0 R:0
GATE
FILTER
CUTOFF
0
RES
0
LP BP HP
V1 V2 V3
VOLUME
REGISTER WRITES

SID PLAYER

select a sid file
Last Ninja
Ben Daglish & Anthony Lees
1987 System 3
SELECT TRACK
Frame: 0 | 0:00

THE SID CHIP

The legendary MOS 6581/8580 Sound Interface Device - essentially a professional synthesizer on a single chip. Designed by Bob Yannes, who later founded Ensoniq.

Three-Voice Architecture

Each voice has its own oscillator, waveform selector, ADSR envelope, and can produce:

  • Triangle: Soft, mellow tone for flutes and bass
  • Sawtooth: Bright, buzzy harmonics for strings
  • Pulse: Variable duty cycle, most versatile
  • Noise: Pseudo-random for percussion/effects

ADSR Envelope

Each voice has a dedicated envelope generator:

  • Attack: Rise time (2ms - 8 seconds)
  • Decay: Fall to sustain (6ms - 24 seconds)
  • Sustain: Held level (16 levels)
  • Release: Fade out (6ms - 24 seconds)

Programmable Filter

Multi-mode resonant filter applicable to any voice combination:

  • Low-Pass: Warm, muffled tones
  • High-Pass: Thin, bright tones
  • Band-Pass: Vocal, nasal tones
  • Notch: HP+LP combined

Chip Versions

MOS 6581 (1982-1986): Original chip, 12V, darker filter sound. Used in "breadbin" C64s.

MOS 8580 (1986-1994): Revised design, 9V, cleaner filter. Used in C64C and C128.