Mastering Your ZX Microdrive, by Andrew Pennell and published by Sunshine Books.

Those who've been hanging around for over a year for a glimpse of the much-coveted ZX Microdrive and Interface 1 units, will be happy to know that they won't have to wait so long for the inevitable selection of 'how to' books to grace the bookshelves. Already two texts are available on Sinclair Research's new offspring, both of which attempt to fill the gaping holes left by the 'official' Microdrive/Interface 1 manual.

The first is called The Spectrum Micro Drive Book, written by Dr Ian Logan (of long-standing Spectrum fame) and priced at £5.95. Having assisted in the writing of the 'shadow' ROM software for the Interface 1 device. Dr Logan is certainly well-placed to write on the subject. And if it's technical questions you have, Dr Logan is the one who seems to have all the answers.

At first glance, the book looks more like an engineer's manual than a book on programming. The author has detailed the extended Spectrum system, the extended Basic, the Microdrive, the Local Area Network and the RS232 link, to the point where you could almost imagine seizing the soldering iron and building one yourself. Even though a short paragraph warns the reader that the author has been unable to break Sinclair Research's confidence on certain facts about the Microdrive, there's enough information on the unit to keep the most inquisitive happy. And no doubt someone a little less scrupulous will tear the system apart in the future.

The final chapter of the book deals with machine code, and as such rightly demands a large chunk of the text. After a detailed explanation of the various 'hook' codes (which with their association with the 'shadow' ROM are, as expected, covered very well by Dr Logan), there is a section showing how Basic statements can be formed, complete with four new ones especially created for us.

The second book, Mastering Your ZX Microdrive, written by Andrew Pennell and priced at £6.95, takes an alternative kind of approach. Here the author illustrates each command and programming technique associated with the Microdrive/Interface 1 units with a small program so that you can instantly test the power of your expanded system. The book even contains a database program, although I'm not convinced that its inclusion has been that necessary to the overall form of the text.

All the areas of interest are covered, illustrated by some nice programming tricks which might well save the user some agonising hours steaming away at the keyboard. For instance, the author has included a program to change the syntax of the cumbersome LOAD/SAVE/MERGE/VERIFY/CAT/RUN commands, and another which simulates the ON ERROR GOTO command found on many other computers which rival the Spectrum in this elevated form.

Although not having had access to quite the same technical insight afforded Dr Ian Logan, Andrew Pennell has come up with a book that offers thoughtful inclusions for the Microdrive/Interface 1 user. But I'm not sure of the relevance of the cover picture which sets the Microdrive high in the sky, godlike above a sparse desert - I didn't find the writing to be that dry!

Even though both books are pitching themselves at the same market, neither detracts from the other, Dr Logan's effort holds up as the manual which maybe Sinclair Research itself should have taken the trouble to bring out, whilst Andrew Pennell's offering provides enough useful text for you to want to start tapping away at your keyboard. The Microdrive/Interface 1 units are obviously going to stimulate many other authors to put pen to paper, drawn by the complexity and scope of the devices themselves, and the potential size of the market for books that deal with them.

Both the present books are well worth the read, and full marks to the publishing companies involved.

Melbourne House and Sunshine Books, for meeting the challenge so quickly - it just seems a shame Sinclair Research couldn't do its bit by making the devices available to the computing public with quite the same enthusiasm.

PUBLICATIONS OF VARYING QUALITY AND QUANTITY HAVE GONE ON SALE DURING THE YEAR. JOHN GILBERT LOOKS AT THE GROWING BOOKSHELF AND SELECTS SOME TYPICAL EXAMPLES OF RECENT DEVELOPMENTS.

YOUNG AUTHORS GET OPPORTUNITY.

John Gilbert assesses publishing.

The Computer publishing market has developed so quickly this year that publishers have been desperate to lay their hands on anyone who knows something interesting about Sinclair computers, programming techniques, or who has some programs they want to sell.

Some publishers have even asked teenagers to write books because insufficient adult writers have been able to get to grips with the subject. That kind of move sets a precedent in the publishing industry. No other sector has ever sought young writers with such vigour. If you can write and you have an above-average knowledge of computers there is a good chance that a publisher will contract you for at least one book. The problem is, and has always been, that young writers know little about the publishing industry and, through no conscious fault of the signing company or the young author, writers do not obtain everything they should. Fortunately that does not happen often but it is a side-effect of the market growth and the urgency with which publishers seek titles. The youngest writer of the year must be Patrick Bossert, author of the Penguin You Can Do The Cube. In August, Penguin released one of its first micro-computer books by the 14-year-old. Unfortunately Micro Game: was little more than a book of listings, a stage though which many companies such as Shiva Publishing, Interface and Melbourne House passed earlier in the year.

Penguin seems to have relied on Bossert's fame with the Rubik Cube and that the puzzle and computers share the same intellectual image in the public mind. Just because Bossert can do the cube, however, does not make him an automatic genius at computer programming.

The concepts for most of the programs in his book existed earlier in the year when all you could buy in terms of the Spectrum were books of listings. There is little that is new in the title - a pity, since it is from Penguin, a publisher renowned for its quality of output.

Books of listings were popular at the beginning of the year when the ZX-81 had more of the limelight than the Spectrum. Authors such as Tim Hartnell were having at least one book published a month. Most of those books were for the ZX-81, as most publishers had not yet advanced to the Spectrum, although it was launched in April, 1982.

Before the beginning of 1983 the only publishers to try for something extra from the ZX-81 were Interface, Melbourne House and Shiva. All were still small but it is a mark of their innovation which shows their success and expansion to date. Now all three have a large share of the publishing market where Sinclair machines are concerned.

By May all three companies had done something different for the Spectrum market. Machine code programming for the Spectrum was a subject which would sell books and the big three publishers knew it.

Shiva produced Spectrum Machine Code, by Ian Stewart and Robin Jones. It was launched as part of the Friendly Micro series and, although it did not cover the area in as much depth as some of the American books about the Z-80 processor, it provided an excellent grounding in machine and assembly language. It also added a humorous element missing from many other books with 'bug' cartoons spread throughout the pages.

The other publisher renowned for its stock of titles on machine code is Melbourne House. It has two machine code titles which cover the ZX-81 and Spectrum. Both are similar in approach and it seems as if the Spectrum version was edited from that of the ZX-81, with extra examples showing colour and sound added.

The other range of machine code books from Melbourne House is by Dr Ian Logan and, in the case of The Complete ROM Disassembly, written with Dr Frank O'Hara. The books are excellent value and contain a good deal of necessary information for the machine code programmer.

Because of his knowledge of the Spectrum ROM, Logan was asked by Sinclair Research to write the routines for the Microdrive ROM. As a result, and with the blessing of Sinclair Research, he wrote the Spectrum Microdrive Book. It includes much information about the drives, Interface One and the possibility of adding or patching-in extra commands to the Basic.

The emergence of the book resulted in a rash of similar texts from publishers trying to keep in the race for the most up-to-date information. In most cases the follow-up texts represented a rearrangement of the original but, unfortunately, that is not so with the new Microdrive texts from Interface and Sunshine Books.

When first exhibited at the Personal Computer World Show in September, the Interface book was little more than a slim cardboard-bound photocopy. It was planned to use it as the basis for a 'proper' publication. The Sunshine effort, however, was better-presented.

The author of the Sunshine Master Your ZX Microdrive is Andrew Pennel, a friend of Logan. His book contained information which Logan's could not. One reason was that he was not limited by what he could say. Although Logan speaks with an authority which is difficult to match, Pennel's book is slightly better as it contains information which Sinclair Research did not want used in Logan's book.

Even with the restrictions, however, the Logan book is good value so far as money and information are concerned.

The release of the Microdrive texts has introduced a new area to the computer publishing market. We have had books on machines, books of listings, and books showing software techniques but there had, until then, been no books on one specific peripheral for a machine.

The Microdrive seems to have opened an area which could soon include how to get the best from your sound generator or using a disc drive with a Spectrum. Book titles such as that may seem absurd now but with the way books are becoming so machine-dependent, and with the search for new areas to write about, such titles may become available.

The information in the Melbourne House book on the Microdrive contains a good deal of machine code. The publisher is still determined to introduce machine language anywhere it can and the release of another machine code book for the Spectrum was inevitable before too long. The new book is Supercharge Your Spectrum and many pages are occupied by machine code listings. They include routines to search for strings in programs, re-number lines, and delete blocks of lines. It has proved extremely useful to Spectrum owners who know nothing about machine code but who want toolkit routines without having to buy several cassette-based programs.

It is useful in another respect. It is possible for someone just learning about Z-80 machine code to read the program listings and get an insight into how programs are structured and the way in which some statements can work with others. It also provides an incentive to use some of the routines in your own machine code programs.

Not all publishers are interested in machine code and the market has plenty of support from companies with other ideas. Yet another new type of book was launched for the Spectrum by Sunshine. Until the release of Spectrum Adventures, by Roy Carnell and Tony Bridge, computer owners interested in adventure games-playing or writing had to rely solely on magazines.

The new book improved that situation, however, and showed the reader how to write graphics adventures. Little is said about decoding player responses or generating textual adventures but the book still marks a new area for publishers to exploit.

While the areas which belong to the games and utility sector have developed by leaps and bounds, the business and education markets are still nothing more than a mess. Little has been done in book form to aid this ailing though very important part of the industry. There have been a few general books on business applications, such as Databases for Fun and Profit from Granada, but little business-orientated work has been done.

The same is true of the education market, although some publishers, such as Granada and Longmans, are starting to see the potential. The object seems to be to produce as many programmer-orientated books as possible. Unfortunately that leaves the market for the computer user who does not want to be bogged down by technology as undeveloped as it was early in the year.

Several new areas in the publishing industry include machine code programming and programming techniques. They are over-developed and that is proving expensive to the other users who want to use Spectrums at home or at school for accounts or homework.

In the end that can only do the market and, indirectly, computer manufacturers, a good deal of harm. The areas in which computers can be used, such as education and business, will be under-developed. Many children will know how to program but very few will have ideas on how to use those programming talents.

Interface, 44-46 Earls Court Road, London W8 6EJ.

Melbourne House, 131 Trafalgar Road, Greenwich, London SE10.

Puffin Books, Penguin Books Ltd, Harmondsworth, Middlesex.

Shiva Publishing, 4 Church Lane. Nantwich, Cheshire CW5 5RQ.

Sunshine, 12-13 Little Newport Street, London WC2R 3LD.

Grenada, 8 Grafton Street, London W1X 3LA.