HyperSID Manual - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -HyperSynth
SID legend:
The SID was designed by a young engineer named Bob Yannes, who was with a company
named MOS Technology in 1981. This company was a supplier for Commodore and Yannes
and his team got the task to construct a sound chip for the upcoming C64 Home computer
within a timeframe of only four months! The result was a big achievement but due to the
highly limited time a few things were not really perfect and the chip have several hardware
bugs .The name SID was given from “
SOUND INTERFACE DEVICE
” and it became the first
digital synth in a computer.
The SID is a mixed-mode integrated circuit, featuring both digital and analog circuitry. All
control ports are digital, but the output ports and the filter are analog.
SID Chip features:
3 Tone Oscillators Range: 0-4 kHz
4 Waveform per OSC : Tri, Saw, Variable Pulse, Noise
3 Amp modulator range: 48 dB
3 Envelope generator Exponential response
Attack Rate: 2 ms - 8 s
Decay Rate: 6 ms - 24 s
Sustain Level: 0 - peak volume
Release Rate: 6 ms - 24 s
Oscillator Sync
Ring Modulation
Programmable Filter
Cutoff range: 30 Hz - 12 kHz
12 dB/octave Roll off LP, BP, HP, Notch
Variable Resonance
Mater Volume Control
At first version the chip was published with part number 6581 and the next revision was
8580.
The 6581 and 8580 differ from each other in several ways. The 8580 was thus far more
durable than the 6581. Additionally, a better separation between the analog and the digital
circuits made the 8580 chip's output less noisy and distorted.
The filter is also different between the two models, with the 8580 being closer to the actual
specification but Many SID musicians prefer the flawed 6581 chip over the corrected 8580
chip.
