SwinSID based on ATMEGA88

SwinSID Nano/Micro
Firmware 2012-05-24
Firmware for 32MHz ATMEGA88

SwinSID based on ATMEGA8515

SwinSID X2 hybrid board
Build instruction

Detailed part list and build instruction of dual AVR hybrid board with SID socket  for use in C64. Board design by Crisp.
SwinSID X2 (C64 TDA1543) Firmware 2010-04-16 Main firmware with mono output and 8580 compability.
SwinSID X2 (C64 TDA1543A) Firmware 2010-03-02 Firmware with support for TDA1543A DAC. Not recommended - see below
SwinSID X2 (STEREO SPLIT) Firmware 2010-04-16 Firmware with "stereo split" mode to split three SID voices into two stereo channels.
SwinSID X2 (MIDIBox version) Firmware 2009-08-20 Improved filter cutoff range, strong resonance and hi-freq white noise generator. For TDA1543 DAC
SwinSID X2 hybrid board
EAGLE schematic
Dual AVR with SID socket and address decoder
SwinSID X2 hybrid board
EAGLE board layout
Hybrid SwinSID board: SID socket + 2xAVR and TDA1543 DAC
Board designed by Crisp.

Building tips

  • Overclocking ATMEGA8515 to 24MHz is really safe. You don't need to worry, it won't spoil or even become hot.
  • You need to setup AVR fuse bits correctly after first firmware flashing. Setting fuse bits incorrectly may cause AVR to stop working.
  • Third overtone crystals won't work with SwinSID. If you experience problems with running SwinSID like very low sound pitch use fundamental frequency crystal or integrated crystal oscilator.
  • TDA1543A DAC has more complex bus protocol and requires special firmware to run correctly. Because this prorocol takes more CPU time this DAC is not recommended as it slows down processing.
  • Both master and slave AVRs on hybrid board runs the same firmware versions.
  • After every reset SwinSID plays short test tone. The tone frequency is 1000Hz on main core and 500Hz on slave.
  • SwinSID X2 firmware is compatible with hybrid board as well as with simplified single layer PCB, however the red LED won't work.
  • Optionally SID socket on hybrid PCB can be used to improve compability (reading SID registers) and generate sound on standard C64 audio output.
  • You can use 8bit PWM output to playback sound without DAC, just connect B0 AVR pin with 4,7K resistor to AUDIO OUT SID socket pin. You also need to add bias by connecting 4,7K from +5V to AUDIO OUT pin.

SwinSID SE (discontinued)

Stereo reverb effect with sinlge AVR. For TDA1543 only
Source code
Full ASM source code including waveforms.
Single AVR schematic image
Single AVR board layout (view from the top, 600 DPI)
Single sided PCB for easy soldering.

If you have any questions about this project or need help with building SwinSID just mail me.

All files from this page are intended for testing purpose only, for non-commercial usage