In the restoration of the Harwell Dekatron / WITCH computer, we wanted to change as little as possible, particularly the external appearance.
Our main objective has been to restore it to a state where it can be reliably and safely operated at the Museum for demonstration to the public and educational groups.
This computer has had a uniquely long working life during which it has been extensively modified and repaired. For example, a number of design improvements were made at Wolverhampton to improve reliability. We have made no attempt to return it to an original condition and in some cases our work has added another chapter to the history of the machine. In particular the power supply unit now contains an example of almost every type of rectifier technology from 1950 to the present day! The modern replacements are hidden from view, with the original components left in place.