This category covers everything, from discrete solid-state memory chips which more or less mimic the action of the electro-mechanical setter, through to computer-based systems, either with dedicated micro-computer systems or using a personal computer to memorise settings.
The key benefits available from computerised systems can include:
• Multi-level memories. For example, 64 or 128 separate sets of combination settings for different organists or different styles of playing might be recorded on one system and selected at the press of a button or move of a switch.
• Archiving of settings by downloading onto commercial memory storage and then uploading should a visiting organist re-appear.
• Settable range, whereby the stops that each piston controls can be pre-defined by the organist from the console
• Sequencing, whereby repeated pressing of a single piston brings on a series of pre-defined registrations (rarely applied in theatre organ playing)
• Utilities to facilitate copying of ranges, settings, recall of changes etc.
The exact possibilities depend on the design of the systems, which become ever-more sophisticated with time.