For ATTiny85 and ATTiny84
This is a Library of Arduino Sketches that can be loaded on ATTiny AVR microcontrollers to use in lo-fi synth/noise circuits. Either replacing a block of logic or creating a new type of circuit block altogether. The intent is not to create a synth on a chip, but to have a series of building blocks to create richer devices with an actual lower device count. Rather than write the code to tailor the circuit, these are a prewritten library of sketches that can be used to plug into your breadboard or whatever.
Kinda like if you discovered a whole new series of CMOS chips like the 4000 series.
Of course, these are really arduino chips with the limitations that come with that such as speed, quantization and code quirks. I am focusing on ATTiny85, 84 and 2313 for the most part. Again, these are components, not full blown products. There are a few things out there with similar concepts.
MiniMoSynth A Formfactor and open source/open hardware design to make ATTiny Blocks. Certainly the closest to what I have here. I do not really have a consistant strategy nor a consistant input like these little blocks. Check em out.
Rad-fi System from Bleep Labs Uses Arduinos as building blocks for Synths on a breadboard. A collection of ATTiny micros with these sketches would be completely compatible with this system. Bastl Kastle uses 2 ATTiny85s that can be programmed with other features.
Electric Druid has some AVRs and others as building blocks. For example, an LFO.
Ability to program ATTiny chips. This only requires an arduino uno, a handful of ATTinys and a breadboard. And whatever you were doing before to build a lunetta like circuit or Nand synth or whatever.
Link to the Wiki is here
Simple sketches that act as VCO, LFO and oscillators. Some complex tones are here as well if there is room for a pin, but generally anything more than a two tone siren sound is going to be a component.
Envelope generators, VCA
Modulation. Adders, Mixers, dividers, Multiplexers, Gates, Vibrato
Shift, Delay, Samplers, Melody Makers, Atari Punk Console.
Things that are generally more complex than a simple vca, vco and so on.
Interface, Control, Midi, Visualization
Wacky and weird stuff