The world-famous original MOS 8580R5 or 6581 SID chip for the Commodore 64.
The sound of the two SID versions differs, partly due to differing filter capacitors, partly due to the greater number of possible waveform combinations with the newer SID.
 
Thoroughly soak-tested replacement SID chip for the Commodore 64
  - 6581 is 12 volts is suiatble for "Longboards" from the C64 Breadbin/Breadbox
  - 8580 R5 is 9 volts and is suibale for use on "Shortboards" C64c C64 MKII boards.
 
 
Way Too Much Technical Data
3 independant oscillators with ADSR control
4 waveforms: square, triangle, sawtooth, noise (can be mixed)
High/low/band pass filters (can be mixed)
2 cascadable ring modulators
Synchronisation of two oscillators
2 8-bit A/D converters
 
* Images are for illustration only.
 
* The 8580 SID chip should only be used in the later C64c -
Replacing a 6581 (from an original Breadbin)? Do not be tempted to install a 8580 SID into a long-board (breadbin) as you will damage it as the power is wrong (6581 is 12 volts, 8580R5 is 9 volts).
 
A new low-cost replacement SID chip is available from us here.