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Unformatted text preview: ing as and when required.
3. Processing. Performing arithmetic operations (add, subtract, multiply, divide, etc.)
or logical operations (comparisons like equal to, less than, greater than, etc.) on data in
order to convert them into useful information.
4. Outputting. The process of producing useful information or results for the user,
such as a printed report or visual display.
5. Controlling. Directing the manner and sequence in which all of the above operations
The goal of this chapter is to familiarize you with the computer system units that perform
these functions. This chapter will provide you with an overview of computer systems as
they are viewed by computer system architects.
The internal architectural design of computers differs from one system model to another.
However, the basic organization remains the same for all computer systems. A block
diagram of the basic computer organization is shown in Figure 2.1. In this figure, the
solid lines are used to indicate the flow of instruction and data, and the dotted lines
represent the control exercised by the control unit. It displays the five major building
blocks, or functional units of a digital computer system. These five units correspond to
the five basic operations performed by all computer systems. The function of each of
these units is described below.
Data and instructions must enter the computer system before any computation can be
performed on the supplied data. This task is performed by the input unit that links the
external environment with the computer system. Data and instructions enter input units in
forms that depend upon the particular device used. For example, data are entered from a
keyboard in a manner similar to typing, and this differs from the way in which data are
entered through a scanner, which is another type of input device. However, regardless of the form in which they receive their inputs, all input devices must provide a computer
with data that are transformed into the binary codes that the primary me...
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This document was uploaded on 04/07/2014.
- Spring '14