The sound is split into small chunks called granules. These may then be processed in various ways to acheive various effects - for example, to stretch a sound (timestreching) the granules will be played back so as to overlap each other. An interesting effect can also be obtained by playing the granules backwards....
OB-X
"Oberheim released the polyphonic and programmable OB-X in 1979. Available in four-,
six-, and eight-voice configurations, it offered 32 program memories, polyphonic
portamento, and polyphonic sample-and-hold."