The data from the OPAL detector was recorded electronically, and processed automatically. The purpose was to reconstruct precisely the trajectories of charged tracks, and the positions and energies of particles which shower in the calorimeter. It was important to have the means to visualize the raw data and the reconstructed results, in order to validate the reconstruction process, and to help the physicist understand the data.
In Cambridge we wrote the software which allows OPAL physicists to display events. A wide range of different displays is available, and the program ran using standard software packages on all the different kinds of computers used in OPAL at the time. You can look at an extensive selection of events recorded in OPAL. On the right is an example (of a Z boson decaying into quarks).