"Dr. Wily's Castle" theme from the NES game Mega Man 3, composed by Yasuaki Fujita and Harumi Fujita.
This recording was made using a modified virtual NES sound chip, the 2A03. It was emulated from a modified NSFPlay. The source code is available from my GitHub repository: https://github.com/kylxbn/nsfplay
The modifications are as follows:
- Floating point mixing and volume adjustment for all channels
- Linear mixing of all 2A03 channels (to avoid DPCM/Triangle volume loss)
- Triangle wave is generated with a pure (non-quantized) triangle wave
- Triangle wave is volume-compensated with an equal loudness contour (ISO 226:2003)
- Noise subsampling is downsampled with floating point math (not audible, to be honest)
- VRC6 sawtooth wave is generated with a pure (non-quantized) sawtooth wave
- VRC7 mixing is done in floating point to prevent quantization noise
- N106 updates channels simultaneously per sample, instead of a round-robin implementation
- N106 actually mixes channels instead of multiplexing each channel
- maybe some small tweaks I forgot