Ian Williamson & Rodney Dale
Experience has shown that every 'revolution' from the industrial one onwards (and before that such innovations as fire, metal extraction, the wheel, bows and arrows, and so on) has brought with it its prophets of doom and destruction.
Experience has also shown that the benefits of each 'revolution' are generally demonstrable, and that their disadvantages are quickly absorbed into what one might think of as the inherent 'disadvantage level' of civilisation. In our view, though the microprocessor will undoubtedly cause many changes, it will, then it comes into the perspective of hindsight, appear little different from any of the other scientific changes of the century-such as the ability to take to the air, or harness nuclear power.
Electronics, computers, minicomputers, microcomputers, microprocessors-all affect our lives, yet for some reason little has been done to make them understandable; indeed, it seems almost as though there has been a deliberate effort to make them completely incomprehensible. Perhaps those who understand think that their knowledge gives them power over lesser mortals, and that if it were seen how simple it all is, their power would be lost.
Perhaps the experts know something we don't. True, the subject is complex, and the technology is advanced, but that does not excuse those who understand from explaining the basics. Not everyone can be an expert, but nobody should be left in doubt as to what the genus computer can and cannot do. After all, the experts needn't fear that the man in the street will rush forth and start to manufacture computers, any more than motor manufacturers fear that a wider understanding of the internal combustion engine will put them out of business.
Ever since the lazy but ingenious Humphrey Potter took his ball of string and improved the so-called 'fire engine' lately invented by Mr Newcomen by causing it to operate its own valves (the task for which Potter was employed), we have been able to make things work themselves more efficiently than we can work them.
We know that if we could wind the handle at 6000rpm in the teeth of various forces resisting us we could push our car along the road as well as its engine can. We do not spend much time marvelling at the reliability of our motorcar engine: rather do we curse it when it doesn't start. Our sense of wonder is proportional to our sense of understanding. A motor engine runs at 6000rpm each piston reverses its direction or motion 200 times a second and we don't turn a hair.
Do you think a player piano is 'clever'? Probably not. Why not? Because player pianos have been around for a long time, and you have some understanding of how they work, the fact that they are mechanical and large takes the mystique away from them. The 'cleverness' of the player piano rests in the way it works, not in what it does. It rests in the inventors and developers of player pianos, not in some quality inherent in the (man-made) mechanism.
The same applies to electronics, computers and microprocessors. At a different level, perhaps, but we (mankind) have not yet succeeded in making anything 'clever' than ourselves. We can run the player piano at the limit of its speed of response, and it will play its tune in a way which far outshines the dexterity of any human performer but that's not 'cleverness', and we don't feel threatened by it. It is interesting that we don't feel threatened by pocket calculators; perhaps it's because there is some comforting relationship between pressing the buttons and getting the answer. Generally, we don't feel threatened by machines we understand. Yet when we don't understand them, the story is very different. In today's equivalent of stoning the misfit, or breaking up looms, we enjoy articles of 'news' about computers which send out daily gas bills for £0.00 or telephone bills for £521,784.
We ought to stop and think more about our reaction. If you are reading this book, a page of English prose or poetry presumably holds no terrors for you. Yet if you cannot read this line of Aramic you'll probably not lose any sleep;
The symbolic language below, by Scarlatti, does not worry you why? You may not be able to play it, but you understand the principle behind it the correlation between the symbols and the eye, via the brain to the fingers, via the keyboard to its mechanism, via the strings to the air, via the ear to the brain, so that the listener can (if he knows his Scarlatti) call that knowledge out of his memory, exclaim: '23 in E major!' and sing the next few bars.
When a computer can do all that, we may need to start worrying, but we'll show that it's some way away yet. However, enough of all this analogy. We have shown that incredibly complex things happen every minute of every day without our becoming particularly worried about them, because we (think we) understand them. Or at least we know that we could understand them if we put our minds to the problem.
The purpose of this book is to tell you what microprocessors are, what they do, and how they are made.
We start by showing you their relationship to computers, so that in telling you about one we are telling you about all. We do this via a discussion of programming, language, and what goes on inside computers. We refer particularly in this part to the control of a washing machine.
The second part of our book looks at the way a computer operates, given that it is merely a vast collection of switches. We then introduce the semiconductor, the seimconductor switch, and the method of building a large number of such switches on a chip of silicon.
Part three looks at the history of aids to calculation, and shows the chain of events which has led to our present-day achievements.
Part four aims at putting the extravagant claims made for the microprocessors into perspective. We give what we hope to be an antidote to today's scaremongering and over-hopeful prediction.
Our intent is (to borrow a word from another discipline) to demythologise the microprocessor, and in doing so enable you to evaluate the claims made for it.