Here’s what he has to say about it:
I just uploaded a pretty big collection of waveforms from the System 100 synthesizer.
Essentially, it’s just a series of simple waveforms (saw, square, triangle, noise) but what’s interesting is it’s completeness, typically I’ve sampled each note over a 6 octave range and for each note there are 8 velocity layers with different filter settings. When used with a sampler, that allows velocity morphing (like EXS24 or Kontakt), so you can simulate the sound of the filter opening and closing.
I given it up to the public domain, so there are no restrictions on it’s use.
It’s a free download via the Modular Samples site.