Keysplit Patch
C1 to B1 is a kick which is being produced by the module labelled 'OSC1' in the grid (it's a sine wave being rapidly pitch swept down). Click on the 'OSC 1' tab at the bottom left of the screen to look at the Osc1 settings. Notice the 'Key -> Gain' diagram - the rectangle formed by the grey lines and green pixels is showing that for the notes lying underneath (the octave above C1) the gain (~volume) for Osc1 will be 100% and for all other notes 0%; Osc1 will only sound for this octave.
From C2 to B2 'Noise1' is producing a very crude analogue snare. The Noise modules don't have a dedicated settings section, so the keysplitting/mapping is instead managed using ModMapper1 (right hand side of the screen) which is routed to modulate Volume in the Noise module.
From C3 to B3 is something like bongo/congo. The 'Comb' module is producing the tone, the keymapping is Modmapper2 routed to Comb volume.
Hope that helps and feel free to use this patch as a starting point.

