PERSONAL COMPUTERS
Personal computers are supposed to appear in the late 1970s.
One of the first and most popular personal computers was the Apple II, introduced in 1977 by Apple Computer. During the
late 1970s and early 1980s, new models and competitive operating systems seemed to appear daily. Then, in 1981, IBM entered the fray with its first personal computer, known as the IBM
PC. The IBM PC quickly became the personal computer of
choice, and most other personal computer manufacturers fell by
the way-side. One of the few companies to survive IBM's onslaught was Apple Computer, which is sure to remain a major
player in the personal computer marketplace. In less than a decade the microcomputer has been transformed from a calculator and hobbyist's toy into a personal computer for almost everyone.
What is a personal computer? How can this device be char- acterized?
— First, a personal computer being microprocessor-based,
its central processing unit, called a microprocessor unit,
or MPU, is concentrated on a single silicon chip.
— Second, a PC has a memory and word size that are small
er than those of minicomputers and large computers.
Typical word sizes are 8 or 16 bits, and main memories
range in size from 16 К to 512 K.
— Third, a personal computer uses smaller, less expensive,
and less powerful input, output and storage components
than do large computer systems. Most often, input is by
means of a keyboard, soft-copy output being displayed on
a cathode-ray tube screen. Hard-copy output is produced
on a low-speed character printer.
— A PC employs floppy disks as the principal online and
offline storage devices and also as input and output me
dia.
— Finally, a PC is a general-purpose, stand-alone system
that can begin to work when plugged in and be moved
from place to place.
Probably the most distinguishing feature of a personal computer is that it is used by an individual, usually in an interactive
mode. Regardless of the purpose for which it is used, either for
leisure activities in the home or for business applications in the
office, we can consider it to be a personal computer.    APPLICATION OF PERSONAL
COMPUTERS
Personal computers have a lot of applications, however, there
are some major categories of applications: home and hobby,
word processing, professional, educational, small business and
engineering and scientific.
Home and hobby. Personal computers enjoy great popularity
among experimenters and hobbyists. They are an exciting hobby. All hobbyists need not be engineers or programmers. There
are many games that use the full capabilities of a computer to
provide many hours of exciting leisure-time adventure.
The list of other home and hobby applications of PCs is almost endless, including: checking account management, budgeting, personal finance, planning, investment analyses, telephone answering and dialing, home security, home environment
and climate control, appliance control, calendar management,
maintenance of address and mailing lists and what not.
Word processing. At home or at work, applications software,
called a word processing program, enables you to correct or
modify any document in any manner you wish before printing
it. Using the CRT monitor as a display screen, you are able to
view what you have typed to correct mistakes in spelling or
grammar, add or delete sentences, move paragraphs around, and
replace words. The letter or document can be stored on a diskette for future use.
Professional. The category of professional includes persons
making extensive use of word processing, whose occupations are
particularly suited to the desk-top use of PCs. Examples of other
occupations are accountants, financial advisors, stock brokers, tax consultants, lawyers, architects, engineers, educators and all
levels of managers. Applications programs that are popular with
persons in these occupations include accounting, income tax
preparation, statistical analysis, graphics, stock market forecasting and computer modeling. The electronic worksheet is, by far,
the computer modeling program most widely used by professionals. It can be used for scheduling, planning, and the examination of "what if situations.
Educational. Personal computers are having and will contin- ue to have a profound influence upon the classroom, affecting
both the learner and the teacher. Microcomputers are making
their way into classrooms to an ever-increasing extent, giving
impetus to the design of programmed learning materials that can
meet the demands of student and teacher.
Two important types of uses for personal computers in education are computer-managed instruction (CMI), and computer-assisted instruction (CAI). CMI software is used to assist the
instructor in the management of all classroom-related activities,
such as record keeping, work assignments, testing, and grading.
Applications of CAI include mathematics, reading, typing, computer literacy, programming languages, and simulations of realworld situations.    Найдите в текстах  PERSONAL COMPUTERS и APPLICATION OF PERSONAL
COMPUTERS слова:
a) близкие по значению следующим словам:
Verbs: to print; to produce; to convert; to keep; to found; to
erase; to name; to change; to use; to start; to switch on; to supply; to give possibility; to involve.
Nouns: rate; analyst; possibilities; use; plays; control; post;
mode; profession; consultant; teacher; director; book-keeper;
fight; producer; attack; amateur; device; crystal; error; storage;
primary (memory); monitor; characteristic; aim.
Adjectives: flexible; thrilling; main; little; general;
b) противоположные по значению следующим словам:
Verbs: to finish; to switch on; to take; to delete.
Nouns; online; input; work.
Adjectives: cheep; weak; common; general; large; soft; high;
easy.