Machine Code Applications for the ZX Spectrum: Expert Machine Code Techniques

Big K

NAMING THE GUILTY MEN Let's kick off this month with a real goodie , Micromania (Sphere, £1.75), for my money the best introductory book available, and certainly the rudest and funniest. Written by Charles Platt (USA) and adapted for Britain by Davin Langford, it sets out to tell 'the whole truth about home computing' and does it with knowledge, wit and style. Aimed mainly at people hovering on the brink of, or with one toe in, the murky waters of the hobby, it manages to put the boot firmly in on virtually every aspect. The chapter on manufacturers ('Naming Names'), is alone worth the price of admission and really shows up books like Tim Hartnell's Personal Computer Handbook'. Commodore get a particularly brutal savaging, but virtually all manufacturers stagger out of the ring covered in blood. Even if you've already taken the plunge, there's plenty of good demystifying gen on, for instance, 'Translating Computer Magazines Into English'. Of course, book s like this always suffer from being a bit out of date, even when revised as this one has been, it doesn't tackle the thorny issue of MSX and went to press before Atari opened the latest price war, for instance. Even so, warmly recommended if only for the jokes. The Micro Enquirer (Century, £8.95) on the other hand has no jokes, is excessively polite about everything and is as boring a book as you could hope to find. It's a format series of which about 90% is standing copy while the rest is specific to the Spectrum, 64, BBC or Atari XL. Put together from material in Another Computer Magazine, there probably is some juuice to be squeezed out of this bland little fruit, but overall it's too tedious for the general reader, and not technical enough serious computer freaks. Putting 'The Indispensible guide to your computer' on a book jacket sounds well OTT, but I must admit that Chris Williamson's Getting the Most Out of Your BBC Micro (Penguin, £5.95) really does live up to it. Very clear, well laid out and to the point, it pulls off that rare trick in computer writing - of treading the thin line between flannel and techno-gibberish, and actually being straightforwardly informative. Apart from picking up where the official 'User Guide' leaves off, it fills in the inevitable gaps. Should be in the box with every Beeb. Building Blocks for BBC Games by Bruce Bayley (Melbourne House, £6.95) has the best printed game listing I've ever seen, beautifully clear with Checksum validations to boot. Unfortunately the games themselves look dull as ditchwater. (The giveaway is the strip on the cover saying 'Electron Compatible'). About a third of the book is actually given over to examining sub-routines, the 'building blocks' of the title, showing the applications of structured programming. Robert Young and Roger Bush, the authors of Games Commodore 64 Computers Play (Addison-Wesley, £6.95) should be published by Melbourne House, if only because they're fellow Aussies. From their biogs they're obviously both heavy duty wargamers, but it doesn't show much in this selection of 19 listings. About half are arcade games, a quarter abstract strategy numbers and the rest adventures or simulations. A pity that Addison-Wesley went for reproducing dot-matrix printouts, which vary from fairly crisp to virtually invisible, because the games sound more interesting than most. I mean Sunnybrook Farm and Roman Empire? Change the ribbon next time, lads. CBM 64 Programs Vol 1 (Duckworth, £6.95), programs by Richard Franklin, edited by Nick Hampshire, suffers, if not quite so badly, from the same problem. A large chunk of the book is devoted to high-res graphics via machine code, with music, utilities, sprites, user-defined characters, a long Star Trek game listing, plus a medieval stag-night adventure and a clutch of smaller games. 'As anyone who has tried to use their Commodore 64 at all seriously will know, the version of BASIC that it is equipped with is not the most advanced version around'. Thus Peter Gerrard introduces, with classic understatement, his Advanced BASIC & Machine Code for the Commodore 64 (Duckworth, £6.95). In his usual thorough style, Gerrard, a really serious 64 man, sets out to go beyond those slow motion PEEKs and POKEs, using an arcade game to introduce the rudiments of machine code programming. Unlike its stable mate above, it boasts crystal clear listings, an excellent appendix of useful information summaries and a proper index.

Personal Computer News

John Lettice

'Machine Code Applications for the ZX Spectrum' by David Laine, published by Sunshine Books at £6.95 (paperback, 160 pages). The number of introductory books to the Spectrum is legion, and introductions to Spectrum machine code are not far behind, but books on machine code techniques for the more experienced programmer are much thinner on the ground. David Laine's Machine Code Applications for the ZX Spectrun is intended to fill this gap in the market and presents the advanced programmer with a number of useful routines. Though it is not for the beginner, the book kicks off by explaining how you should approach machine language, and gives some timely tips on programming techniques. Next is a quick turn through the instruction codes, number representation and addressing, and straight into a few listings. Once you're further into the book and the machine. Mr Laine presents routines to handle floating point numbers, output to the screen, animated graphics and Basic block delete. Of course, there may not be much more around as yet, but by the time you've finished reading, you should really be writing it yourself, right?