see one demo here: https://www.youtube.com/watch?v=t5Bt15cpJzY
Generalmusic GEM PK7 music keyboard. These are very rare and I have come across none (other than this one) for sale online. This one is from 1998 and although that may not appear to be vintage it is in keyboard terms. Features: 61 key velocity sensitive keyboard Pitch bend wheel Volume slider 95 onboard beats 127 onboard patches (instruments/sounds) Demo button 2 number pads for sound/beat selection Onboard sampler (recorder) 4 programmable pads In-built speakers Metronome Tempo wheel Cursor position and up/down arrows (works like a mouse) for data entry Floppy disc drive for expansion Midi in/out Joystick lead Lcd screen This keyboard is in full working order (its a bit dusty) with only a few light scratches.