I took a shot at modeling the TR-909 using synthesis for all except the hats and cymbals. I can’t honestly say it sounds better than kits built with samples, but I had fun and I think it sounds pretty good.
The synth techniques used are mostly adapted from descriptions of how the sounds were constructed in the hardware.
The file is saved as a project as it contains several Rack Presets. So please load as a project, not an instrument.