Electronics technicians are frequently required to diagnose faults in equipment but are not provided with adequate training in TAFE Colleges. Hardware fault simulators currently used in TAFE Colleges for diagnostic skill development simulate only a few types of equipment and rapidly become obsolete. FAULTSIM is a computer-based simulator in which modern technology is combined with existing simulation techniques to produce a versatile aid to diagnostic skill development. In the design of the new simulator, attention has been given both to the technical features contributing to its effectiveness and to the factors favouring its adoption by teachers.