I completed the first prototype of Almagest in July 1989, using plywood, cardboard and a throat lozenge tin. To start with, a Sinclair ZX Spectrum did the math and controlled the wheels; then this task was transferred to an embedded microprocessor. Back then, its range was just 100 years (from 1900 to 2000), and the zodiac ring was fixed, but its functionality was basically the same as that of the final model - not that it always worked.
To become a saleable product, the clock had to be comprehensively redesigned. The process of model-building and testing went on for several years. Many people were involved in the project; my friend Julian Atiyah was the one who got the whole thing going.
Almagest was put together in a small factory in Wiltshire; the mechanical parts, oak case and integrated circuits were all made in England. It made an appearance on Patrick Moore's BBC program 'The Sky at Night'.
Buyers of the clock received a comprehensive handbook with user instructions and other useful reference material.