This keyboard is in good condition, considering its age. All keys respond to playing, including aftertouch.
This is an incredible synthesizer.
Two digitally-generated waveforms can be mixed and combined through a fairly intricate effects stage to create extremely iconic 80s sounds or something quite unique and unusual.
The effects stages are all analog, with varying degrees of precision on each parameter.
In fact, I think the parameters may be more or less digitally controlled based on the coarse steps on a few of them.
The Korg DW-8000 synthesizer is an eight-voice polyphonic hybrid digital-analog synthesizer 61-note keyboard instrument released in 1985.
The Korg Poly-800 is a 49 key (4|8 voice polyphonic) synthesizer, featuring dual oscillators (additive square waveform, single oscillator in 8 voice mode), white noise, 24dB resonant low pass analog filter, dedicated volume and filter ADSR envelopes, LFO (routed to pitch, filter, volume), sequencer.
Physically, the instrument used a 61-note synthesizer action keyboard. "Synthesizer action" means that it did not have weighted or semi-weighted keys, a common feature on stage pianos marketed at pianists.
The DW-8000 keys are velocity sensitive.
As such, a light press triggered a quieter sound and a hard press triggered a louder sound.
As well, its keys could sense channel-pressure aftertouch as well. Aftertouch is the placing of pressure on keys after the initial striking or pressing of the keys.
On a digital keyboard with aftertouch sensitivity, when the performer continues to press the keys, the aftertouch sensors send a message to the synth module; depending on the programming of the synth patch and/or the settings selected by the performer, aftertouch can trigger a digital effect (e.g., vibrato) or a change in the timbre (tone color).
The keyboard sends aftertouch messages via MIDI if required.