The drum-machine SR-16 released by Alesis was launched in the early 90's, and had a tremendous success. It includes 233 sounds of realistic "dry" signal live drums, and pre-sampled ones processed with digital reverbs. The unique "Dynamic Articulation" function allows you to alter percussions, and is velocity sensitive.
SR-16 provides 50 preset patterns that were studio recorded by the real drummers. In SR-16, you can find rhythmic variations (switching between A/B and 2 sections "Fill") to create full loops, and also save your own individual patterns and songs.
The device has a full MIDI implementation (input, output/thru), an input for a foot switch, flexible programming, and 12 velocity sensitive pads, each of which hiding drums: kick, snare, hi-hat, clap, tom, raid, crash and percussion. SR-16 was used in the studios of the famous duo Autechre, and by no means less legendary Vangelis.