« This book was written for people who feel that they would like to get more out of their computers than games and writing large business programs. The computer should be used as a TOOL for the job in hand, as it makes a helpful companion which does not tire and will carry on quite happily twenty four hours a day.This book shows how this tool can be used in various applications and how the computer can turn itself into many things: a ther­mometer, voltmeter, burglar alarm, all costing a lot less than many specialised units. The computer is a programmable device that can be altered to suit any home, business or pleasure application, tailored to your own needs by YOU.This book is based on a IK ZX81, but most of the projects in this book can also apply to TANDY TRS80’s, PET’s, TANGERINE’S, SHARP MZ80K’s etc. »