By far, the most fun way to play drums in Atomic Sound is by picking some good samples for each channel of a Drumboto, pressing start on the drum kit to activate it, then moving the cursor over to the Drumboto's Live button, and pressing A. This will put the drum into a special 'Live' mode that is tied directly into the velocity sensitive controls of the Drumboto.
IMPORTANT: The cursor will be stuck here until you press the BACK button to exit Live mode.
While Live mode is active, the four pads and the foot pedal are tied directly to channels in the Drumboto.
Where it gets interesting is pressing Start on the drums when in Play Live mode. This causes the splitscreen viewport for the drums to be turned off (press start to show it again). This allows a second controller to be activated - usually a game pad - which can be used to navigate around the rack and tweak settings and adjust cables while you or a friend are playing the drums.
The Drumboto velocity sensitivity is tied to two dials on the front: Dynamic and Range. These affect the volume level and pitch of the currently selected channel. Setting these in the middle causes velocity to have no effect. Higher values cause volume and pitch to go higher with harder drum hits. Lower values cause them to go down with harder drum hits.
Protip: Pressing A while over the channel dials will allow you to then press combo A+Dpad Up/Down to change the active channel, making adjusting settings faster & easier.
The velocity of the drum channels are available as control voltage outputs on the back and can be routed to other channels or devices to suit your creative experimentations. It can be fun to have these connected to pan or fade controls - or both, if you route them through a control signal processor which can manipulate the signal in various ways before being fed into the next device in the chain. That's an advanced use though; to start it out just try banging on the drums in Play Live mode.