It all started a couple of months ago, when I encountered a 23-byte C-64 demo, Wallflower by 4mat of Ate Bit, that was like nothing I had ever seen on that size class on any platform. Glitchy, yes, but it had a musical structure that vastly outgrew its size. I started to experiment on my own and came up with a 16-byte VIC-20 program whose musical output totally blew my mind. My earlier blog post, “The 16-byte frontier“, reports these findings and speculates why they work.

Some time later, I resumed the experimentation with a slightly more scientific mindset. In order to better understand what was going on, I needed a simpler and “purer” environment. Something that lacked the arbitrary quirks and hidden complexities of 8-bit soundchips and processors. I chose to experiment with short C programs that dump raw PCM audio data. I had written tiny “/dev/dsp softsynths” before, and I had even had one in my email/usenet signature in the late 1990s. However, the programs I would now be experimenting with would be shorter and less planned than my previous ones.

I chose to replicate the essentials of my earlier 8-bit experiments: a wave generator whose pitch is controlled by a function consisting of shifts and logical operators. The simplest waveform for /dev/dsp programs is sawtooth. A simple for(;;)putchar(t++) generates a sawtooth wave with a cycle length of 256 bytes, resulting in a frequency of 31.25 Hz when using the the default sample rate of 8000 Hz. The pitch can be changed with multiplication. t++*2 is an octave higher, t++*3 goes up by 7 semitones from there, t++*(t>>8) produces a rising sound. After a couple of trials, I came up with something that I wanted to share on an IRC channel:

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