**About this book** This manual serves both as a beginners' introduction to computing in COMAL and as a reference manual for the more experienced user. COMAL is recognised in many European countries as one of the best languages in education. It has the facilities for writing well-structured programs and includes excellent interactive debugging responses. Its ability to handle procedures, functions, strings and arrays, and its other advanced features place COMAL in the forefront of microcomputer languages. This manual introduces the user to the Acornsoft implementation of COMAL. The first section takes the form of a tutorial course for the user who is new to programming. The second contains the information which a user already familiar with BASIC or Pascal will need to write software in COMAL. There is then a reference section containing a complete summary of the language by keyword as well as various tables, and finally a number of demonstration programs. **About the authors** Roy Thorton read Mathematics at Royal Holloway College, University of London. Following service in the Instruction Branch of the Royal Navy he became a schoolmaster and is currently Director of Computing at Portsmouth Grammar School. Paul Christensen is currently studying Natural Sciences at Churchill College, Cambridge University, having previous attended Portsmouth Grammar School.