I have created a a 4 step 4 channel sequencer, which I planed to make out of real discreet hardware, and I would be happy for any suggestions for improvements, although this software is pretty much used to its limit. The simulator I used was the only one I could find that allowed for different pitch outputs, and it sounds best at the higher speeds. This is from 2 years ago, I seem to remember something disappearing from my save file.
The design for this project is complete within the simulator, but I am abandoning this is favour of a modular 16 step sequencer. I have been speaking to a musician friend lately about what he needs in an instrument and have decided that if I am going to build one, it will be much better than this. Parts are on order, so I may post a new project within a month.
thanks for that neuroproducts.be link - I've made a t-flip-flop from nand logic so I'm able to build a 4011 ring modulator for my synthesizer with it ( well researched and thrown together by stuff others made long ago is a better description...)