The 1541 is one of the least understood of the Commodore peripherals; a lousy manual, dotted with mistakes and omissions, leaves people under-utilsing what can be a flexible add-on. Many people are content only to LOAD and SAVE programs and sequential files, little realising the power available through use of relative files, and the direct access commands.

Well, the good news is that all these, and more, are dealt with adequately in an easily-understood style in this book from Abacus. As well as explaining the ordinary DOS commands, the book goes on to explain relative files, the direct access commands and the internal structure of a 1541 diskette - the block availability map, the directory, and so on.

Many useful utility programs are given. These programs are an education in themselves, demonstrating many of the commands dealt with. The Disk Monitor program in particular is excellent - it allows easy editing of individual disk sectors, useful for patching up messed disks.

The authors even document the 1541 TEST-DEMO disk programs, including the DOS wedge, giving the instructions that Commodore forgot...

For the really keen, the authors also give a fully commented disassembly of the DOS 2.6 ROM, discovering a new command in the process.

This book I recommend to anyone who has got lost in the 1541 user's manual, or those of you who want to utilise your disk drive to the full.

Overall, worth having.