TABLE OF CONTENTS Because binary digital coding is so error-resistant (page 211), it is used for the various internal operations of most modern computers. Analog electrical signals are still used for many purposes such as local telephone calls, and for some types of fairly simple computers in automation, etc. However, relatively small but very powerful desktop computers, and also some large supercomputers, now use digital "microprocessors" for their internal operations. In each of these, most of the action takes place on one silicon IC "chip." A large single crystal of silicon is grown by slow cooling from a melted pool, and this is later sliced to form a "wafer." That gets donor or acceptor atoms diffused into various regions of it, making mostly CMOS transistor pairs. Then the wafer is diamond-sawed to make hundreds of smaller "chips," each one of which is almost a whole computer. Of course, it also needs to be attached to a keyboard, and a TV-type screen, etc.
The internal operation of such devices is beyond the scope of this quite simplified laboratory course. Suffice it to say that the binary digital programs for these microprocessors consist of extremely long lists of binary (zero or one) numbers. This is called machine language.
Groups of these numbers, somewhat summarized into a symbolic format, are called object code, and this is considered to be a sort of "language," at a slightly "higher level" than the raw zeros and ones. Programs for running the computer can be written in...
