Shelton Instruments Limited, of White Lion Street near Angel Tube Station in London's Islington, had been started back in 1970i[source: http://www.theregister.co.uk/2013/08/21/unsung_heroes_dr_chris_shelton/] by Chris Shelton, who ended up working a stint at Nascom - once the UK's top selling kit micro manufacturer - where he designed the Nascom 1. The advert is for the Sig/Net, which Shelton also designed - a modular system which was CP/M "compatible". The base unit supported one user with a floppy disk, but additional units could be stacked to add more users or more disk storage. A single module started from £1,400 - about [[1400|1983]] in [[now]].