Understanding Computer Graphics

ZX Computing

Patrick Cain

There can be few areas, if any, of computer development whose application is so wide spread as computer graphics. Yet, perhaps, it is because of the advancement in this area that we overlook or are unaware of many of the applications. As everybody knows, the Walt Disney studios used computer graphics extensively in the film 'Tron'. Computer graphics are used more and more in film production, as they are in television, cartoons, painting, sculpture and other art forms; but their application spreads far beyond these. Readers of 'Understanding Computer Graphics' by Judy Tatchell and Les Howarth are quickly put in the picture about a variety of applications. As with the rest of the books in the series the publishers have gone to some length to support the text with many bright illustrations. Indeed the format resembles a comic book with illustrations and text being freely mixed and the maxim of one picture being worth a thousand words is well proven. As a result many complicated notions are expressed in a fashion that is equally suitable for younger and older readers. The discussion throughout the book is non technical, being less concerned with an analysis of computer graphics than with highlighting the varied application. By the time the reader has gone through the 48 pages he will be aware of a number of everyday uses and the principles behind them. The book is a worthwhile read at a number of levels; it should help to answer in part the ever recurring question "what do computers really do"; it will give computer users an appreciation of other computing areas and it may serve to whet the appetite for further knowledge sated only slightly by the few program examples at the back. What the book did for me was to quickly draw me a picture of a lot of computer applications I may have missed altogether because I would never have been sufficiently curious to spend sufficient time to look. And for that alone it was a valuable read. 'Understanding Computer Graphics' is written by J. Tatchell and L. Howarth. ISBN 0 86020 739 0.

Personal Computer News

Nickie Robinson

Inside The Chip, by H Davies and M Wharton, Understanding Computer Graphics, by J Tatchell and L Howarth, Machine Code for Beginners, by L Watts and M Wharton, all published by Usborne, at £1.99 paperback, £3.99 hardback each 48 pages. These three slim volumes for beginners are colurfully illustrated making them easy to read. Robots demonstrate the tasks of the computer, some of them biking along eight pathways to eight section garages representing eight bit bytes, while others pin up notices or choose library books, depicting RAM and ROM. Colour is cut off towards the end of each book, and black and white pages bring them to a less visually stimulating close. Understanding Computer Graphics, by far the easiest to read, begins by describing how a picture is produced on screen and includes a clear explanation of the size of memory needed to produce pictures of differing resolution and colour. The rest of the book is dedicated to practical aspects of computer graphics - simulation, computer aided design, animation and computer art. The book ends with four graphics programs to run, with conversion charts for the BBC, Spectrum, Dragon and Apple. Inside the Chip starts enticingly with an illustration of a silicon chip beside an open tube of sweets. But the going gets tougher with explanations of registers, control circuits and logic circuits, among others. There are interesting sections on how chips are made and their origin and design. Practical circuits are included for those who like to dabble. Machine Code for Beginners is a brave attempt to simplify a difficult subject. Having fought through the explanation you have the opportunity to test your new-found skills by writing a simple program to add two numbers together. If you make this hurdle you are ready for flags, jumps, subroutines and conditional branches. You'll know you've arrived at this testing section of the book - it will be in black and white.