Computer
Literacy
It is difficult to think of a field in which
computers are not used. In addition to general-purpose computers,
special-purpose computers are used in everything from automobiles to electric
razors. Consider how computers have influenced our daily lives, both positively
and negatively. (“To err is human, but to really foul things up requires a
computer.” – Anonymous, from a BBC Radio broadcast.) List ways in which
computers are being used today. What is the most common use? What is the most
unusual use? As a result of the expanding use of computers, in 1986 Florida
Computer
Although computers are thought of as a relatively
recent innovation, the term computer has a long history. Prior to 1940,
“computer” was a job title that referred to anyone performing calculations.
Consider how data is different from information.
Data is processed into information. Clifford Stoll – lecturer, computer
security expert, and author of Silicon Snake Oil: Second Thoughts on the
Information Superhighway – notes a wide gap between data and information. Stoll
insists that information has a pedigree, or lineage. Its source is known,
whether by a respected professor or a seventh grader. “The Internet has great
gobs of data,” Stoll maintains, “and little, little information.”
The first three operations in the information
processing cycle — input, process, and output — are performed to process data
into information, while the fourth operation — storage — refers to a computer’s
electronic reservoir capability. Think about how we perform each phase in the
information processing cycle in the “human computer” (i.e., the human brain)
while completing a common task, such as learning a telephone number.
Computer
Components
Different types of input devices are designed to
transmit different types of data or to transmit data in different ways. Think
of other input devices (joysticks, scanners, digital cameras, and so on) and
the different types of data they transmit or the different ways they transmit
data.
Because it is more lasting than output from a
monitor or speaker, the printer’s output often is called hard copy. Think of
other output devices with which you are familiar (data projectors, computer
output microfilm, and so on).
Some computer components are considered internal,
while others are considered external. External components are called
peripherals. Input, output, and communications devices often are peripheral
devices.
The difference between the temporary character of
memory and permanent nature of storage will be made painfully clear the first
time you experience a power failure while working on a computer. Think of other
examples of storage devices (magnetic tape, PC Cards, and so on).
The capability to communicate may be one of the
most significant factors influencing how computers are used now and in the
future.
Computer
Power
In one billionth of a second, an electronic signal
travels almost 12 inches. This means that today’s supercomputer (the fastest,
most powerful, and most expensive category of computers) can perform 1.8
trillion operations per second. If a person did one arithmetic operation a
second without stopping, it would take more than 31,000 years to perform the
number of operations a supercomputer can do in one second. Researchers predict
that one day computer speed will be measured in exaflops, or one quintillion (1
x 1018) calculations per second.
The reliability of computer components often is
measured in MTBF (mean time between failure, in hours). A typical component
might be rated 10,000 MTBF.
Although the term “computer error” is widespread,
most computer errors can be traced to human mistakes. Consider instances of
computer error with which you are familiar. How might human blunders have
resulted in the computer error? Why are people apt to blame computers?
Supercomputers have more than 600 gigabytes of
memory, meaning that they can store more than 600 billion letters, numbers, and
special characters, and have 2 terabytes (2 trillion bytes) of disk space.
Equally important is the speed at which data can be retrieved, processed, and
stored again.
Connected computers can share each operation in
the information processing cycle. To recognize the value of communication,
imagine trying to solve a problem individually, and then trying to solve the
same problem with the assistance of several classmates.
Computer
Software
The difference between computer hardware and
computer software is important. A 3½-inch floppy disk is hardware; however the
programs stored on it are software. Programs or software, like data, are input
into the computer.
Because you interact with it directly, you may be
more consciously aware of application software than system software. Remember
that system software determines how you interact with application software.
Popular operating systems include DOS (Disk Operating System), Windows 3.x
(technically, not an operating system but an operating environment that makes
DOS easier to use), Windows 95, Windows 98, Windows 2000, Windows XP, Mac OS,
OS/2, UNIX, Linux (rhymes with cynics), and NetWare. DOS was developed by
Microsoft for IBM personal computers. DOS started Microsoft’s climb to the top
of the software world -- at one time, versions of DOS were used worldwide by
more than 100 million people. DOS has a command-line interface, meaning that
people have to memorize and type instructions.
Today, operating systems with a graphical user
interface, such as Microsoft’s Windows, are far more popular.
Most application software packages are designed to
be used with specific operating systems. Much of the software with which you
are familiar is packaged software. Because of their complexity, most software
programs are written by teams of programmers working together. Just as people
understand a variety of spoken languages (English, French, Chinese, and so on),
computers recognize a number of programming languages.
Networks
A network with which you might be familiar is the
school computer lab. Consider resources that can be shared on a network. For
example, the school computer lab may share a single printer. Think of
advantages of sharing resources. Why are most business computers part of a
network?
The Internet
Estimates claim that more than 50 percent of U.S.
Computer
Categories
In addition to differences in size, speed,
processing capabilities, and price, other factors, such as the size of main
memory and number of peripheral devices, also can be considered when
categorizing computers. Rapid changes in technology make it difficult to define
categories precisely. As a rule of thumb, today’s PCs have about as much memory
and processing power as the mainframes of a decade ago.
Think of personal computers with which you are
familiar. How is the computer used? What factors influence the choice of a
personal computer? In addition to such obvious considerations as processing
speed and amount of memory, less apparent factors, such as available software
or even the computer’s “footprint” (the amount of space it occupies on the work
surface) also may be important. A desktop computer monitor often is placed on
top of the system unit case. This sometimes can be an ergonomic problem,
forcing users to look up. Server computers often are used in academic
environments. What features of server computers would make them particularly
attractive to schools? In today’s mobile society, notebook computers have
become indispensable tools. Since 1993, sales of notebooks and smaller
computers have rivalled sales of larger systems, partly because of their
enhanced capabilities and increased use by field sales forces. The capabilities
of handheld computers also continue to expand. Visor, a new handheld computer
from Handspring, is an electronic organizer but also offers video games, a cell
phone, a modem, an MP3 player, and a two-way pager. Called the “Swiss Army
knife of handheld computers,” Visor uses the Palm operating system, which is
the same operating system used by the Palm Pilot, a popular handheld computer
from 3Com, and is available for about $200.
The growing movement toward decentralization in
business, coupled with the increasing power of mid-range servers, has led to a
recent trend away from mainframe computers and toward mid-range servers. What
advantages might mid-range servers have over mainframe computers for a
business?
Organizations that deal with huge, constantly
changing collections of data accessed simultaneously by many users, such as
banks, insurance companies, universities, and government agencies, often use
mainframe computers. Despite this, mainframe sales are declining approximately
10 percent per year.
One of the most important features of
supercomputers is their capability to create complex, three-dimensional images
almost instantaneously. Television networks often use supercomputers to
generate complicated images and then give viewers the sense of “going through”
the image. Due to their size and expense, only large businesses and government
agencies use supercomputers. IBM’s Option Blue supercomputer was used by the
Department of Energy to simulate nuclear explosions, allowing the effects of
aging and adverse conditions on nuclear weapons to be explored without
underground detonations.
Types of
Computer Users
A major concern related to the home user is the
digital divide, which is the idea that the people of the world can be separated
into two distinct groups: those that have access to technology with the ability
to use it and those that do not have access to technology or are without the
ability to use it. Recent reports suggest that the digital divide exists on
several levels:
Individuals in higher income levels have greater
access to the Internet than people in lower levels and the gap may be growing.
Women are under-represented in today’s computer
classes and technology jobs.
A number of efforts are being made to narrow the
digital divide.
Networks have changed the face of both small and
large business. In the 1970s, executives usually worked with monthly reports;
in the 1980s, they used weekly reports; today, daily or even hourly reports are
available. How have computers affected the efficiency of businesses? What
impact have computers had on the “interpersonal” side of business (i.e.,
employee and customer relationships)? How have computers changed people’s jobs?
Have computers cost any people their jobs?
Web
Publishing
With today’s Web page authoring software, children
as young as 10 years old, and sometimes younger, can create and publish their
own Web pages. If you created a Web page, what type of information would you
provide? Why? Would you be interested in seeing someone else’s Web page? Why or
why not? If you have created a Web page, what type of software did you use?
What was the most difficult part of creating your Web page?
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