INFORMATION:

Room 1 of three.
It had two floors and the bomb aimers would occupy a position the first one from where, through a hole in the floor, they had a view of the ground floor on which would be projected a rolling map showing the detailed terrain of their target area. Numerous variables could be simulated of which the bomb aimer would have to compensate.
Extract from - East Devon Aircrew & Airfields ISBN 0-9539015-0-5