But How Do It Know? - The Basic Principles of Computers for Everyone
Format: PDF / Kindle (mobi) / ePub
Finally, this brand new book exposes the secrets of computers for everyone to see. Its humorous title begins with the punch line of a classic joke about someone who is baffled by technology. It was written by a 40-year computer veteran who wants to take the mystery out of computers and allow everyone to gain a true understanding of exactly what computers are, and also what they are not. Years of writing, diagramming, piloting and editing have culminated in one easy to read volume that contains all of the basic principles of computers written so that everyone can understand them. There used to be only two types of book that delved into the insides of computers. The simple ones point out the major parts and describe their functions in broad general terms. Computer Science textbooks eventually tell the whole story, but along the way, they include every detail that an engineer could conceivably ever need to know. Like Baby Bear's porridge, But How Do It Know? is just right, but it is much more than just a happy medium. For the first time, this book thoroughly demonstrates each of the basic principles that have been used in every computer ever built, while at the same time showing the integral role that codes play in everything that computers are able to do. It cuts through all of the electronics and mathematics, and gets right to practical matters. Here is a simple part, see what it does. Connect a few of these together and you get a new part that does another simple thing. After just a few iterations of connecting up simple parts - voilà! - it's a computer. And it is much simpler than anyone ever imagined. But How Do It Know? really explains how computers work. They are far simpler than anyone has ever permitted you to believe. It contains everything you need to know, and nothing you don't need to know. No technical background of any kind is required. The basic principles of computers have not changed one iota since they were invented in the mid 20th century. "Since the day I learned how computers work, it always felt like I knew a giant secret, but couldn't tell anyone," says the author. Now he's taken the time to explain it in such a manner that anyone can have that same moment of enlightenment and thereafter see computers in an entirely new light.
eight things it can do, and for some of those things it uses two bytes of input, for other things it only uses one byte of input. And in seven of those cases, it has one byte of output. This type of instruction will choose one of the ALU operations, and two registers. This is the most versatile instruction that the computer can do. It actually has 128 variations, since there are eight operations, and four registers, and you get to choose twice from the four registers. That is eight times four
reader with the details. Reading a program like the one above is an entirely different skill than reading the diagrams and graphs we have seen so far in the book. I hope you were able to follow it, but no one is expected to become an expert at reading programs because of this book. Division also can be done by our computer. There are several ways it can be done, and we are not going to examine any of them in any detail. Just imagine the following simple method. Lets say you want to divide
they change between on and off when they are told to do so. Computer bits aren’t like the coin that has to physically flip over to change from one state to the other. Bits don’t change shape or location, they don’t look any different, they don’t move or rotate or get bigger or smaller. A computer bit is just a place, if there is no electricity in that place, then the bit is off. When electricity is present, then the bit is on. If you want to change a coin from showing heads to showing tails, you
direction, a one. Once a spot is magnetized, it stays that way unless the same spot gets magnetized the other way. Turning the power off has no effect on the magnetized spots. A disk, as its name implies, is a round thing, that spins around quickly. It is coated with a material that can be magnetized easily. Do you remember the telegraph? At the receiving end, there is a piece of metal with a wire wrapped around it. That piece of metal turns into a magnet when electricity moves through the wire.
code. Its purpose is to make it easier to write computer programs. In order to use this language, you write the program you want with ASCII characters, and save it into a file. Then you load a special program called a ‘compiler’ into RAM and jump to its first instruction. The compiler will read the ASCII file, translate each line into the Instruction Code that it represents, and write all of the Instruction Code bytes into a second file. The second file may then be loaded into RAM, and when the