Drumbox was updated on December 28, 2008 to fix a few bugs and to add more interactivity. The new features (along with most of the old ones ;)) are not documented yet, but here is a quick and dirty primer until the real docs get written:
Tap record - This feature enables real time recording via the computer keyboard or mouse. The following keys are mapped to drum sounds:
L,K,J => Low/mid/high tom
S => Snare
Q,W => Open/closed hat
E,R => Ride/ride bell
T=> Crash
H=>Assignable (see below)
F3 starts/stop playback
F2 enables/disables record mode
Using tap record
Pressing the keyboard keys listed above will trigger the associated drum sound. If the track is playing and record mode is enabled then the beats you play will be added to your track, otherwise they will sound but will not be recorded.
If you click your mouse over one of the drum names (left of grid) it will be highlighed in pink. You can either play this sound by clicking with the mouse or by using the 'H' key as this is the sound now assigned to that key.
The usual clipboard keys are active, so for example if you drop in some beats that you don't like you can erase them (undo) with Ctrl-Z. Be careful though, redo (Ctrl-Y) isn't implemented yet! Ctrl-C/V/X do the usual copy,paste,cut operations. To copy or cut you must first select the affected beats.
Selecting beats
You may select or deselect individual beats by clicking on them, hold the shift key to select multiple beats this way. You can also select a group of beats by dragging a select box around them. Selected beats appear as red instead of the usual green. Once you have selected some beats you can copy or cut them. You can also set their volume by moving the volume slider.
Delayed sound?
You may experience a delay between the time you press a key and the actual sounding of a beat. The beats will be placed in the correct timing and will sound at the right time when the track is played, but the delay can make it difficult and confusing to record live. The delay (at least on my computer) was caused by using the Windows built in MIDI synthesizer as the sound generator. When I switched to using a real MIDI synth the delay went away so apparently the delay was introduced by the Windows soft synth.