Launched in 1981, Sir Clive Sinclair's ZX81 - successor to his ZX80 released the year before - was designed to be a low-cost introduction to home computing for the general public. It was a hugely successful machine, with over one and a half million 'official' units being sold; many more unauthorised 'clones' were also produced, particularly in Russia and other Eastern Bloc countries of the era. One could either purchase the machine pre-built, or - as a significant number of consumers did - buy it in kit form for assembly at home at a slightly cheaper price. This 'DIY' approach, encouraged by Sinclair Research, became a core element of the computer's genetic make-up. Those who were comfortable putting together the four silicon chips and other such components were just as keen to poke around the machine's memory, learning as much as they could about its capability; the programs they would write could easily be shared once saved onto a standard audio cassette. It became common for magazines - both from major publishers and their smaller, fan-produced brethren - to feature listings of programs for the home user to type in themselves. This book features thirty such programs, covering everything from card games and shoot 'em ups to utilities and educational software. The 'Not Only' in the title refers to the fact that in addition to the code listings themselves, the book provides the reader with additional programming hints, advanced space-saving techniques (remember, the ZX81 only had one kilobyte of memory!) and general coding advice to up-skill anyone interested in doing so. This 40th anniversary reproduction is the first time this hugely influential and popular book has been printed in decades. Available in paperback form like the original, or a collector's hardback edition, it is the ideal purchase or gift for any fan of the early days of home computing.