| Books |
John Gilbert reviews the latest releases.
THE EDUCATIONAL sector of the book market is expanding but the standard is not becoming noticeably higher. Although the psychology of teaching by computer seems to be developing in the proper direction, the standard of presentation in many cases is not good enough. The explanation is that the books on the market are either too difficult or too easy for the beginner to understand.
The Spectrum Starter Packs, numbers one and two, are for the 48K Spectrum. They suffer from being too easy for the age range at which they seem to have been aimed. The packs do not take into account that most children looking at them are growing up in an age of electronics. They do no more than illustrate points in the Spectrum manual and show how the various commands work on the computer.
Both starter packs contain program cassettes which explain how the computer works and provide examples of the Spectrum Basic commands. Most of the information on the cassettes is dealt with in the books accompanying the packs, so the inclusion of such cassettes is superfluous.
The books could be used in primary schools, although they would be of more value as a talking-point for teachers than an aid which is given to children who are then left to learn programming virtually on their own.
The intentions behind the starter packs seem good but a little more work could have gone into them to improve the presentation. Spectrum Starter Packs, one and two, cost £9.95.
Books on so-called good programming techniques are now forming an important sector of the market. Although most authors fail to inform their readers that there is no best way of programming, the standard of the books is good.
Databases for Fun and Profit, by Nigel Freestone, is one of the good programming books. The author aims to give the reader an understanding of data structures which are used in programming. The book is not machine-specific and should be easily understood by most owners of the ZX-81 and Spectrum.
It starts by introducing the binary and hexadecimal number systems which are associated with computers, particularly with storage and machine code. It then explains how arrays can be used to create a variety of data structures, such as lists, trees and stacks.
When those structures have been explained the author shows how they are used in several types of programs. He shows what is needed to write diary and bank account programs and name and address systems. He also shows how to incorporate arithmetical formulae, such as income tax calculations, into a program to provide some way of processing the data once it is entered.
Databases for Fun and Profit contains much valuable information for anyone wanting to put Sinclair machines to good use. It is published by Granada Publishing and costs £5.95.
Turning from software projects we move to hardware with Simple Interfacing Projects, by Owen Bishop, also published by Granada.
Like the book on databases it is not machine-specific and that makes it different from all the rest. The projects include a real-time clock, a music generator and a ROM board. There are 12 projects which can be built and they are laid out in an easy-to-understand manner. A brief explanation is given of the project and how it works, then the construction details are discussed. As a result the book would be of interest to anyone who has a computer and a basic grounding in electronics. Some experience of programming would also be useful but not essential. Simple Interfacing Projects costs £6.95.
Another book which will be of interest to ZX-81 owners is The Ins and Outs of the Timex TS-1000 and ZX-81, by Don Thomasson. The book looks as if it was written for a readership in the States but it has some relevance in Britain. It explains the hardware of the ZX-81 and includes a complete circuit diagram of the machine.
The author explains how the CPU chip works and gives a detailed account of the pins which feed it with input and output data. A practical knowledge of electronics is necessary for you to follow the discussions in the book and a knowledge of machine code would also be helpful. It is published by Melbourne House and costs £5.95.
A new work from Interface is The Turing Criterion - Machine Intelligent Programs for the 16K ZX-81. The introduction defines computer intelligence as communicating along a wire with something which you are not sure is human or machine.
The problem with the book is that you cannot tell whether it has been written by a human author or a machine, because it is full of listings and not much else.
The book professes to show machine intelligence in action, complete with explanations of how intelligent programs work. Far from doing so the authors have provided a group of listings with information on how to play the games.
The listings are impressive but some of them are lengthy and take hours to enter. It might be better to buy a tape with the listings recorded on it.
Another strange thing is that the book shows how to convert programs from the ZX-80 into ZX-81 programs. Apart from being irrelevant to the subject matter, the idea of typing ZX-80 programs into a ZX-81 seems futile. It costs £5.25.
It is good to see that most publishers are starting to reduce prices as they introduce new titles. All the titles in this month's review cost less than £7. Last year books about Sinclair computers cost anything from £5 to £15.
Many publishers are having to lower prices because of the competition from companies which have just entered the market. As a result the standard should continue to rise and prices should fall.
| 'It describes its workings in detail and does not indulge in technical jargon.' |
The first book to deal with the insides of the Spectrum, Spectrum Hardware Manual by Adrian Dickens, must be a welcome addition to any constructor or student of computers, writes Stephen Adams.
It provides an insight on how the computer works and then describes the Spectrum in detail, including complete circuit diagrams of everything, except the ULA.
The user has to be satisfied with a pin-by-pin description of that device. The author describes its workings in simple detail and does not indulge in technical jargon. The circuit principles are explained but not component by component, except where the author is sure of his ground, i.e., the power supply, CPU and RAM chips.
The video section is a little misleading as it refers to B-Y as BLUE-YELLOW, where in real life the Y stands for luminance - the whiteness of the picture. It gives the adjustments necessary to deal with some problems associated with the video.
One-third of the book is circuit diagrams and descriptions of circuits the user can add to the back of the Spectrum. The author seems a little nervous about suggesting that the user make improvements inside the Spectrum. A port made from a PIO, add-on joysticks, plus an exterior keyboard are also described. One suggestion for model one users only is to allow for 127 extra ports by improving on the decoding for the I/O map.
The differences between the models one and two are pointed out frequently, with photographs to show the components on the circuit board. A "dead cockroach" IC and the transistor across the model two Z-80A CPU are described, along with why they were necessary.