TABLE OF CONTENTS This chapter begins with an introduction to the basic components of a digital computer. It continues with a discussion of the basic microprocessor operations, and concludes with the description of more advanced arithmetic and logic operations.
There are two classes of computers, analog, and digital. Analog computers are automatic computing devices that operate with electronic signals exhibiting continuous variations of physical quantities such as electrical voltages and currents, mechanical shaft rotations or displacements, and are used primarily to solve the differential equations that describe these time-varying signals. Results are normally displayed on oscilloscopes, spectrum analyzers, and pen recorders. A basic component in analog computers is a very versatile electronic device known as operational amplifier [*] or op amp for short.
Digital computers are automatic computing devices that operate with electronic signals exhibiting discrete variations, and are used for a variety of tasks such as word processing, arithmetic and logic operations, database construction, e-mail, etc. Digital computer operation is based on the binary numbering system which, as we learned in Chapter 1, employs two numbers only, zero (0) and one (1). Our subsequent discussion will be on digital computers. Two important characteristics of any digital computer are the ability to store information, and the speed of operation.
Digital computers are classified either as general purpose (stored program) or special purpose (dedicated) computer. A general purpose computer is one in which the sequence of instructions (program) is read into the computer via the input...
