Two further books on disc storage and handling, Disk Programming Techniques For The BBC Microcomputer and The BBC Disk Book published by Prentice Hall and Century Communications respectively tackle this rapidly exploding area of using the Acorn machines. In actual fact, both are based upon the Acorn DFS and only touch on the possibility of rival systems.

Jonathan Inglis and Ian Murray's foray into disc filing for Century adds little to the standard documentation now available and which comes free with some systems. It will cost you £4.95 and might fill the information gap if, for instance, you bought a second-hand system or installed a DFS yourself.

Michael Coleman's tome for Prentice Hall is three pounds dearer but well worth the extra cash. It is a pretty marvellous 244 pages for anyone interested in programming for disc systems. All the technical information is available on the DFS commands themselves and how best to utilise them, the arrangement of stored material on your disc surface and problems that might occur.

The greatest asset of this book are the sections on programming with the BBC/Electron filing system. Discs, of course, can make full random access available to the user and the guidance given here, and backed up by seven case studies in the second half of the book, should help the intending programmer, and the user who wants to learn about what byte is flying where every time that drive whirrs into action.