GEC 4000 series

The GEC 4000 was a series of 16/32-bit minicomputers produced by GEC Computers Ltd. of the UK during the 1970s, 1980s and early 1990s.

GEC Computers started as Elliott Automation with the then ageing Elliott 900 series, and needed to develop a new range of systems. Three ranges were identified, known internally as Alpha, Beta, and Gamma. Alpha appeared first and became the GEC 2050 8-bit minicomputer. Beta followed and became the GEC 4080. Gamma was never developed, so a few of its enhanced features were consequently pulled back into the GEC 4080. The principal designer of the GEC 4080 was Dr. Michael Melliar-Smith and the principal designer of the GEC 4060 and GEC 4090 was Peter Mackley.

The 4000 series systems were developed and manufactured in the UK at GEC Computers Borehamwood offices in Elstree Way. Development and manufacture transferred to GEC Computers new Dunstable factories in Woodside Estate, Dunstable in the late 1970s. In 1979, GEC Computers was awarded the Queen's Award for Technical Achievement for the development of the 4000 series, particularly Nucleus. By 1991, the number of systems manufactured was falling off, and manufacture was transferred to GPT's Beeston, Nottinghamshire factory, and development returned to Borehamwood. The last systems were manufactured around 1995, although there are still a few GEC 4220 systems operating in 2016 with maintenance provided by Telent and some GEC 4310 still operating in 2013.

The GEC 4000 series hardware and firmware included a pioneering facility known as Nucleus. Nucleus implements a number of features which are more usually implemented within an operating system kernel, and consequently operating systems running on GEC 4000 series systems do not need to directly provide these features themselves. Nucleus firmware cannot be reprogrammed by any code running on the system, and this made the systems particularly attractive to a number of security applications.

...
Wikipedia