Imagine (1987)
Arri

Arri Imagine

Memory control for medium & larger sized studios & theatres.
250 or 500 channels, up to 1024 dimmers (512 without optional additional processor card).
3.5" disc backup - up to 1000 cues per disc (1.44Mb).
Up to 28 different cues and effects played back simultaneously.

Imagine 3
From Richard Pilbrow: Stage Lighting Design: The Art, The Craft, The Life
"Designed for mixed rigs of conventional and moving lights, Imagine 3 features 1,536 dimmers with 300, 600 or 1200 channels and up to 1,536 dimmers/parameters."

The 250 channel version was a rebadged ETC Expression.
The 500 channel version was a rebadged ETC Concept

Imagine 250 Systems (partial list):
Norwegian Broadcasting, Oslo
Citizen's Theatre, Glasgow
Key Theatre, Peterborough
Tyne Tees Television, Newcastle
Half Moon Theatre, London
Playlight Hire, Manchester
London Palladium
BBC Belfast
HTV Bristol
Teatro Due, Parma