SwinSID - 16-bit stereo SID replacement built with AVR MCU


    SwinSID is a hardware replacement for legendary SID sound chip placed in every Commodore C64 computer. This extension is designed as a module installed directly into SID socket. It emulates sound of SID chip, but it is lot more powerful and let you experience the new dimension of C64 music.
    Hardware desing of SID and SwinSID module is different in almost any way. My module is equipped with general purpose microprocessor with internal RAM and ROM memory. Programmable device like this has a big advantage - there is a possibility to upgrade firmware to add new features or fixes without any hardware modification.
    SwinSID is based on wave table synth so, any waveform can be stored in memory and playback instead of generating only simple waves like SID does. Thanks this it can produce more complex signal of different instruments. The new mixing modes can also be used for even more rich sound. The polyphony of sound module was increased from only three to six channels with stereo panning and maintain compability with current SID2SID devices in fact it emulates two independent SID chips.
    SwinSID can be used with any of C64 model plugged into SID socket and can replace both old and new revision of SID. To run it, all you need is to open your computer, remove SID chip and put this module in its socket. Power voltage is taken from c64, so special power supply is also unnecessary. SwinSID just emulates almost full register set of standardf SID, and almost all applications, which uses SID, will work with SwinSID too.
    You must notice that SwinSID doesn't sounds like real SID due to some design limitation it introduces low aliasing distortions, but in other way it has improvements from SID in different areas like better ADSR envelope handling and digital, self-oscilating filter. The overall quality of music would be much better when music take advantage of all features of this module and use multiple different waveforms, not available in SID. 
    SwinSID has a very simple design thanks to high speed  processor taking care of everything. The heart of SwinSID is Atmel AVR microcontroller with RISC core running at 24MHz and runs overclocked from default 16MHz, This chip is about 30 times faster than C64's main processor 6510, that gives enough power for real-time audio generating, mixing and processing. Digital sound goes from AVR to high quality 16 bit stereo DAC. At the end of processing we have stereo analog output for external amplifier.



History of development:

2009.11.11
- Fixed bug in calculating filter cutoff
- Released version for TDA1543A DAC

2009.8.20
- New MIDIBox firmware with all current updates from C64 version.
- Updated web site with new photos and detailed info about SwinSID X2

2009.4.15
- New firmware with improved waveforms, filter and noise pitch regulation

2008.5.4
- The new and much improved SwinSID X2 firmware for C64 and MIDIBox was released
- Updated demos section.

2008.1.17
- SwinSID X2 was reviewed by Thorsten Klose, creator of the MIDIBox hardware platform. Read it.

2007.2.17
- New SwinSID SE firmware released with improved TDA1543 support
- New demo music

2006.8.6
- SwinSID SE schematic and firmware are available for download. Check the 'Schematic' section.

2006.6.11
- An interview with me about SwinSID project can be found in CeVi-aktuell 06/2006 - German C64-magazine

2006.4.1
- Photos of the new SwinSID board was added to the gallery.

2005.11.20
- SwinSID2 prototype specification released.

2005.9.13
- Optimized code for speed.
- New effect - duty cycle for pulse waveform. ( With this SwinSID sounds close to real SID. )

2005.8
- Mixing with interpolation

2005.5
- Support for  three voices with 8 instruments and reverb. Added high quality stereo DAC.

2005.4 
- Prototype working in C64 with only 1 voice and 1 instrument. Output is taken from 8 bit DAC

2005.3
- Idea of creating sound module for C64 and first calculations.