Philip.Belben(a)powertech.co.uk wrote : All the "computers" prior to the Manchester machines did not store their programs in memory, they are more accurately termed sequence controlled calculators. The Univac came later, it was actually first delivered in 1951, just a month or so after Ferranti delivered the first commercial computer, the Mark I to Manchester University in February 1951 - and no I don't remember that particular event personally ;-). Again yes, the Manchester machine had a main memory of 32 words each of 32 bits, it had one accumulator and an instruction set of only 6 instructions. It was built in 1948 to prove the reliability of the Williams tube storage system. The very same hardware was then extensively developed into a fully fledged computer over the next two years. Ferranti, under a government contract, built 6 or 7 production versions, the first of which went to Manchester as stated above. Indeed, the interests of the Manchester team were in the hardware design, the Cambridge team were more interested in the programming and uses of computers. So while Manchester developed hardware technologies, Cambridge developed software. Manchester has a long and illustrious history of firsts in the computing area. As well as the first working stored program electronic computer, they were the first to incorporate index registers, the first working transistor computer, and the first virtual memory. That is not to say that others were not working on the same or similar lines, its just that Manchester managed to get there first, sometimes by just a month or two. More info about the Manchester machines and the rebuild project at <http://www.cs.man.ac.uk/CCS/ssem/ssemhome.htm> -- Hans B. Pufal : <mailto:hansp@digiweb.com> Comprehensive Computer Catalogue : <http://www.digiweb.com/~hansp/ccc/> _-_-__-___--_-____-_--_-_-____--_---_-_---_--__--_--_--____---_--_--__--_