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The chip MOS6581 also known as the Sound Interface Device (SID) of the Commodore 64 computer is known for it's characteristic sound. Unfortunately, many of these devices produced between 1982 and 1993 reach the end of their life span these days. It is getting harder to get a replacement part. Thus, we need a proper substitute.
And this is what the FPGASID project is all about!
It has been started to overcome with this situation and reaches even higher - it aims for a better SID than any SID has ever been before...

The Mission

  • Create a pin compatible drop-in replacement for the MOS6581 device as well as for its successor, the MOS8580.

The Targets

  • To-the-cycle exact reproduction of all digital parts including sound and envelope generation and paddle readouts.
  • Exact modeling of the analog parts leading to a result that is almost indistinguishable from the original.
  • Making it configurable to easily switch between various SID variants
  • Adding extra features like wavetables, stereo sound, more voices etc while keeping full compatibility.

The Means

  • Use of FPGA technology. It is more suitable than software related emulation.

The Result

  • This is what came out so far:


  • BREADAMP - The amazing C64 Sample player! Here is something I want to share with you:BREADAMP is a C64 sample player that comes with full featured functionality. It can play various (proprietary) sample formats directly from ...
    Posted Aug 18, 2019, 11:49 AM by andi6510 The FPGASID Project
  • Working on Documentation I have updated the register description document available under Documentation -> Technical Documents.    I made the following changes:Some smaller error correctionsDescribe second role of identify bit (LED control)Describe ...
    Posted Jul 28, 2019, 3:33 AM by andi6510 The FPGASID Project
  • New Firmware release Today I release a new firmware revision 0.A for the FPGASID:Main changes:New 6581 bias setting range and curve. Per default the bias is now tuned to a ...
    Posted Feb 24, 2019, 8:25 AM by andi6510 The FPGASID Project
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