CHAPTER 7
lNPUT/OUTPUT (I/O) AND INTERFACING
INTRODUCTION
The input/output section, under the control of the CPU’s control section, allows
the computer to communicate with and/or control other computers, peripheral
devices, other subsystems (display and communication), and systems (fire control,
sonar, FTAS, and the like). Take the time to understand your computer’s I/O
section: its organization, operation, and interfacing format. The latter is very
important because if the interfaces for the computer and the external equipment do
not match, your computer will not talk to anyone.
After completing this chapter you should be able to:
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Understand the terminology associated with I/O
Describe how your computer’s input/output is organized—hardware
and software
List and describe how the different operating modes affect the transfer
of information
Describe the circuits and their functions in I/O operations
Describe the categories of I/O operations
Recognize how the external equipment in your computer’s system is
con netted
List and describe the types of interfaces used in I/O operations
Describe serial data I/O operations
Describe parallel data I/O operations
Let’s begin your study of input/output with how it is organized in your
computer. The different types of computers vary in their organization of I/O, but
the basic operations of the serial and parallel interfaces are similar regardless of
the computer types.
TOPIC 1—TERMINOLOGY
l ANSI —American National Standards Institute.
You should be familiar with the following terms
l Data Communications Equipment (DCE) —Any
before studying this chapter:
device that communicates the data; for example, a
modem.
. ANEW —Army-Navy Electronic Warfare.
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