Title: The Master 512 User Guide
Publisher: Dabs Press, 5 Victoria Lane, Whitefield, Manchester M25 6AL
Tel.: 061-766 8423
Price: £9.95

As most purchasers have found, buying a Master 512 co-processor is rather like driving a new car without a manual. You know roughly what it is supposed to do, but the details of exactly how it does it have to be found by exploration. As our 512 Forum contributor Robin Burton and his readers complain (see Beebug Vol. 7 No. 7) the Acorn manual is woefully inadequate, and a good replacement is long overdue. Once more the excellent Dabhand Guides fill the gap.

The Master 512 User Guide contains over 200 pages and at a price of £9.95 is excellent value for money in these days when (IBM) PC manuals and handbooks are often over 20. Actually it's part of a set of two: its companion volume, the Master 512 Technical guide (by Robin himself) will be available - says Dabs - at the end of June at £14.95.

The fact that it is the first of a pair actually highlights its principal difficulty: it walks a tightrope between being a replacement for the Acorn guide and being a full technical manual. In the main it performs this balancing act very well, but inevitably when reading it there are a number of times when I want to know more and indeed the book itself refers frequently to the Technical Guide... just have to wait till June I suppose!

The book consists of 19 chapters, a glossary, 7 appendices and an excellent index. The chapters can be grouped into an introduction (with a very clear coverage of directory structures and disc formats: rather brief on the PATH command); GEM (1 chapter); DOS+ commands (7 chapters of 90 pages); batch files (2 chapters); and a series of short chapters at the end on compatibility, expansion (now sadly out of date), shareware and a short question and answer chapter. Putting the Acorn guide to shame are the chapters on ED, PIP, and MEMDISK, which are covered at length. Sixty pages are devoted to a one-by-one listing of the DOS+ commands, both permanent and 'Transient' (i.e. supplied as programs on disc).

Throughout, the explanations use helpful comparisons with other systems (such as ADFS, MS-DOS and CP/M), but little mention is made of the particular problems of the model B/B+ user - I suppose it is a Master 512 user guide.

The appendices cover software compatibility (a straight copy of the list available from Acorn); a DOS+ version compatibility chart and a supplied transient program list; GEM printer codes; Bulletin Boards and a Dabhand Guides Guide(!). There is also a one page appendix on the optional utilities disc.

This latter is available for £7.95 or £5 when ordered with the book. It contains five utilities: a reader for text files (enabling up and down scrolling); a dump utility (like *DUMP); a printer formatter, a customisable menu program, and disc sector editor, which can handle all 512 disc formats. Of particular interest is the inclusion of source code for these (written in C), but you would need a C compiler to modify them.

This book is suitable for beginner and experienced user alike: the layout is impeccable, the explanations clear and the index superb. Sections I would have liked to have seen expanded are those on the batch file processor (I really expected to see a description of how to set up your own menu system) and a 'Tips and Traps' chapter would not have been out of place.

Particularly welcome, however is the section on shareware, which should be of interest to all 512 owners as a source of good software at reasonable cost. All in all highly recommended, and buy the disc too, if only for the disc sector editor. But if you want to know more, then you will need to read the 512 Forum in Beebug until the Technical Manual comes out.