68000 Machine Code Programming

Sinclair User

Overall 4/5

John Gilbert 4/5

Practical Guide to QL Graphics Longman £7.95 Using Your Sinclair QL Hodder and Stoughton £4.95 68000 Machine Code Programming Collins £12.95 The tide of books explaining SuperBasic, the Psion business suite and QDOS was stemmed several months ago when it was discovered the titles were not selling. Some publishers, however, have not been put off and have decided to continue their QL series. Longman launched five titles covering most of the hackneyed subjects but left out a title on graphics and sound. That has been remedied with the recent release of Working with the QL - A Practical Guide to QL Graphics and Sound, by Alan Shinwell. The book covers all the SuperBasic graphics and sound commands and provides a section on Easel, version two. It contains almost nothing new and is just a re-statement of subjects covered in the user guide. There are, however, a few subjects it covers better than the manual and those include stippling, window generation, scaling windows and producing ellipses. It also explains user-defined character generation, a subject not dealt with in the user guide. The section on the QL's limited sound capacity provides a better explanation of the facility than the user guide. The short example programs show how to create scales, produce sound effects and incorporate all those hundreds of Beep numbers into a program with the greatest efficiency. Shinwell does not lack talent in providing the explanations. The problem is that there are already a dozen titles covering this area and one more is unlikely to help the cause of the QL. The same can be said of Using Your Sinclair QL , from Hodder and Stoughton, by Eric Deeson. If the book had been released a year or two ago it would have sold to a captive audience, ready to read anything about the machine. The customer is now more discerning and a book which shows you how to switch on, type things into your computer and how to use the Psion programs is unlikely to cause a stir. The examples of Psion packages used, including a stock control system and a business letter, only show that Deeson does not have a very good imagination. If business users take time to read the Abacus manual they will find that producing a stock control program of their own is easy to do. There is no need to read a book about it. I have no such reservations about 68000 Machine Language Programming, written by David Barrow and published by Collins. It is a down-to-earth guide through the family of processors from the 8/16-bit 68008 to the 32-bit 68020, rumoured to be the chip Sinclair is experimenting with for a new machine. Barrow is an accomplished textbook writer and would probably make a good journalist. There are no frills to his style; the way in which he presents the information makes the reader want to know more. On first impressions the book, with its busy network of complex looking diagrams, threatens to be a titanic tome more suitable for a college library. Unlike many authors, however, Barrow has made every diagram count. The most useful section is for beginners, who have already learnt to use machine code instructions but do not know how to string them together into a large structured program. While Barrow provides long and useful programs for advanced machine coders to get their teeth into he has also aimed the book at beginners. It is an attitude which has worked well.

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