Computers: Definition, Types, and the Computer Revolution
1 The word "computer" is an integral' part of jut about everyone's
daily-use vocabulary, but to many people, it is some kind of miracu
lous "black box, " Technically speaking, the "computer" is any
counting device. But in the context of modern technology, we define
the computer as an electronic device capable of interpreting and exeduring programmed commands for input, output, computation, and logic
operations. The computer, also called a processor, is the "intelligence" of a computer system.
2 Computers come in a variety of sizes, like clothing: small, medium, large, and extra large. We should really add a fifth and sixth
size, very small and superlarge, to cover all types. No matter what
size, all computers operate in the same manner. The difference in size
relates primarily to memory capacity and speed of processing. Where
small- and medium-size units (laptops and PCs--also known as microcomputers) have main memories in the 1 -4MB range, their larger
cousins have multimillion-character memories. A typical PC exe- cutes
hundreds of thousands of instructions per second whereas a
large(mainframe) unit will process many millions per second.
3 At the top of the line are the supercomputers. These are the behemoths of computing. They are so large, powerful, and, of course,
expensive that very few exist. Not many organizations need constant
access to their capabilities. As a result, individuals or
organizations rent the unit for a limited time to do a project. One
or two of these machines could pr6bably handle the majority of library
automation needs in the United States.
4 Next m size is the mainframe e0mputer. Formerly, they were the
giants of computing and for most organizations they still are top of
the line. Mainframes and their auxiliary equipment usually fill up
a large room. They need a dust-free; air-conditioned environment,
special fire protection, and independent electrical power supplies.
For large library systems, for example, the Los Angeles County Public
Library or Los Angeles Unified School District, a mainframe is essential to automate library activities. National library networks such
as OCLC, RLIN (Research Libraries Information Network), and WLN
(Western Library Network) are also dependent on main- frames. Large
Libraries and networks must have the storage capacity and speed of
the mainframe if automation is to be effective.
5 Minicomputers are the medium-size units of computing. Current
models only occupy a few square feet and, if the room has reasonable
temperature and humidity control, require no special environmental
controls. They should have an independent power supply. Most of the
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models are capable of performing at levels that only a mainframe could
manage 8 to 10 years ago. Like their bigger relatives, minis handle
multiple users simultaneously. Most mainframes and minis make
extensive use of terminals (only a CRT and keyboard) for input
and ,output purposes rather than using microcomputers. (Certainly
micros are or could be part of such a network. However, there is little need for the micro's CPU in such cases, as the mini or mainframe
can handle the processing much more efficiently.)
Terminals
through connections to the central computer, can do anything a micro
can and do it more quickly. And a terminal, just a CRT and key- board,
is less expensive than a microcomputer. Most public access to a
library's online catalog is through terminals. Most vendors selling
library automation systems use either mainframes or minis. Only sys~
terns designed for very small libraries use micros.
6 Microcomputers with their auxiliary equipment will fill up the top
of a medium-size desk. They will operate properly at any temperature
in which humans: are comfortable. Obviously, leaving the unit to bake
in 100-degree sunlight or become a block of ice at temperatures below
freezing is asking for trouble.
7 Although you can just plug 'the micro into any appropriate electriCal outlet, this may cause you problems eventually. Electrical power
fluctuates occasionally and sometimes fails completely. In most cases
a complete, quick power failure is better when you are using a computer than a partial failure. A quick failure is almost the same as
turning off the machine. Yes, you will lose the data input since you
last saved your work but losing a few minutes' work (a very good reason
for saving your work every 15 or 20 minutes) is better than having
your machine damaged or your data scrambled. It is the peaks
and valleys in the power that can cause the trouble.
8 Investing in a surge protector ( $ 40 to $ 50) is a small price
to pay to help ensure the integrity of your data and protect your machine. A surge protector is a unit you plug into the wall outlet;
you then plug your computer into the surge unit: Its purpose is to
screen out the surges ,in the power supply and maintain an even
electrical current. (A sudden change in the electrical current's
strength can easily jumble those little magnet{c spots On a floppy
or hard disk. ) For more money ( $100 plus) you can secure even more
protection;
11 The computer revolution is upon Us. This unprecedented technical
revolution has made computers apart of life. With the rapid growth
in the number and variety of computer applications, they are
rapidly becoming a way of life.
The Personal Computer Revolution
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12 The First Personal Computer Boom. For the most part, a microcomputer is used by one person at a time; therefore the micro is
also called a personal computer, or PC for short. The media attention
given to these desktop miracles of technology was intense during their
infant years, the late 1970s and early 1980s. Fear of falling behind
the competition motivated businesses to purchase personal computers
by the truck load. Parents hurried to buy a personal computer so that
little Johnny or Mary could march to the head of the class.
13 Unfortunately, businesses, parents, and others bought PCs
with very little knowledge of what they do or what to do with them.
In fact, the first personal computer boom was actually a bust! A great
many PCs were sold, but relatively few made significant contributions in businesses, homes, or educational, institutions. Because
they were misunderstood and did not live up to ~their fanfare, the
buying public cooled to PCs.
14 The Second Personal Computer Boom. Five years later,, we are
in the middle of the second personal computer boom. The capabilities
of today's micros have expanded greatly. They are easier to use and
people have more realistic and informed expectations of them. The
second personal computer boom is more deliberate. That is, people
are educating themselves about the use and application of micros;
then they are buying them with purpose and direction - the result is
millions of micro enthusiasts.
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Personal computers are everywhere, from kindergartens to
corporate boardroom. You can see them at work, at school, and
possibly in your own home. The most recent boom has made it
possible for people in every walk of life to see first hand the
usefulness of personal computers. Each passing month brings
more power at less expense and an expansion to the seemingly
endless array of microcomputer software. Software is a
collective reference to computer programs that cause the
computer to perform desired functions (for example, word
processing).
Why Are Micros and Personal Computers So Popular ?
16 The minimal cost and almost unlimited applications for the microcomputer have made it the darling of the computer industry. A little more than a decade ago, very few people had heard of a microcomputer. Now the number of microcomputers sold in one month exceeds the
total number of operational computers in existence in the United
States 10 years ago.
17 When you use a micro or personal computer, the capabilities of
a complete computer system are at the tip of your fingers. Some are
more powerful than computers that once handled the data processing
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requirements 0f large banks. PCs and their support software are designed so that they are easy to use and understand. The wide variety
of software available for microcomputers offers something for almost
everyone, from video games to word processing to education to home
finances to inventory control.
18 A personal computer is an electronic version of a scratch pad,
a file cabinet, a drawing board, a typewriter, a musical instrument
and even a friend. It can help you to think logically, to improve your'
spelling, to select the right word, to expand your memory to organize data, to add numbers, and much more.
19 These reasons for the micro's popularity pale when we talk of the
real reason for its unparalleled success--it is just plain fun to use,
whether for personal, business, or scientific computing.
20 Cyberphobia. Computers are synonymous with change, and any type
of change is usually met with some resistance, We can attribute much
of this resistance to a lack of knowledge ab0ut'computers 'and,
perhaps, to a fear of the Unknown. People seem to perceive cumputers as mystical. It is human nature to fear that which we do not understand, be it extraterrestrial beings or computers, Fear6f the computer is so wide-spread that psychologists have created a name for
it cyberphobia. Cyberphobia is the irrational fear of, and a version
to, computer. In truth, computers are merely machines and do not merit
being the focus of such fear. If you are a cyberphobic, you will soon
see that your fears are unfounded as you go on learning about computers.
I. Notes: This reading text is adapted from the Chapter Computers and
Libraries of the book Introduction to Technical Services, the 6th edition by G. Edward Evans and Sandra M. Heft; published by Libraries
Limited, Englewood, Colorado, 1994, and from Chapter One,' Part One
of the book entitled Microcomputers - With Tutorials for Popular
Software Packages by Larry Long and Nancy Long, published by Prentice
Hall, Englewood Cliffs, N.J. , 1988. For in- formation about G. Edward
Evans and Sandra M. Heft, refer to Note 1 of the previous passage.
So far no information .is found of Larry Long and Nancy Long, which
demands further effort in bio- graphical searching.
II. How well did you read ?
1. What is the definition of the computer in the sense of modern
technology?
a. Any counting device
b. A processor or the "intelligence" of a computer system
e. An electrical device capable of interpreting and executing
programmed commands for input, output, computation, and logic
operation
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d. b and c
2. Types of computers are divided primarily by:
a. Memory capacity
b. Speed of processing
c. The way how computers operate
d. a and b
3. What are the characteristics of supercomputers?
a. Huge and extremely powerful
b. Very expensive and very few in existence
c. Rented for a limited time to do a project by individuals or
organizations
d. a, b, and c
4. Which is not true with mainframe computers?
a. They are big enough to fill up a large room.
b. They are essential to automate library activities.
c. They are still giants of computing and top of the line.
d. They need special protection environment.
5. What are the special features of the minis as compared to mainframes?
a. They are smaller and less powerful than mainframes.
b. They need independent electrical power supplies as .mainframes.
c. They are powerful enough as to perform at levels that a mainframe could manage some !0 years ago.
d. They make extensive use of terminals as mainframes.
e. a, b, c, and d
6. Which of the following is not true with microcomputers?
a. They are more adaptable to the environment.
b. They Could occupy only a medium-size desk top.
c. Like other types of computers, they are especially subjected
to the current stability.
d. They could be placed anywhere even in 100-degree sunlight or
at temperatures below freezing.
7. What are the functions of UPS?
a. They are used to achieve a kind of uninterrupted power supply
for computers.
b. They are used to buy the staff time to turn off the equipment
and not lose any data.
c. A UPS functions as a surge protector but more expensive to
maintain a even electrical current for computers.
d. a, b, and c
8. The outstanding features of a laptop computer are:
a. They are surprisingly powerful for their small size.
b. They have communication capabilities and can link to other
computers and download and upload data and share informa-
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tion.
c. Their small size and lightweight will not change when their
storage capacity has become greater.
d. a, b, and c
9. Which of the following is not correct with the computer revolution as mentioned in this passage?
a. Computer technology has undergone a big development in the
past over 30 years.
b. The faster and more powerful the computer is, the cheaper.
e. The increasing number and variety of computer applications
are making computers become a way of life.
d. Today's microcomputers are thousands of times faster and
more powerful than the first commercial computers.
10. What are the reasons for the first personal computer boom?
a. The media's advertising
b. The fear of falling behind the competition in business
c. Parents wanted their kids to march to the head of the class
with computers.
d. a, b, and c
11. What is so special with the second personal computer boom in
terms of the reasons for it?
a. Today's micros have greater capabilities.
b. They are easier to use.
c. People have better understanding of computers and more realistic and informed expectations of computers.
d. They are becoming more and more powerful at less expense
and having-a greater variety of software to perform desired
functions,
e. a, b, c, and d
12. What causes eyberphobia in using computers?
a. The fact that computers are always changing, and any change
is usually met with some resistance
b. The human nature to fear what we do not understand
e. The lack of knowledge about computers
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