What is a computer? I guess the easiest way I can explain it is as a little machine that
follows very specific instructions over and over. A computer cannot learn and, unless
told to do so, won’t respond to anything. Think of it as a very dumb dog that you have to
teach to catch a ball every day and every time you want to play.1
Computers do very complex math. Mind you, it is always related to the basics: add,
subtract, multiply and divide. But as anyone who has had algebra and calculus will tell
you: if you do enough of these basics, you can get approximations of more sophisticated
math that are pretty close to reality. Computers do this math very quickly. Often these
calculations are done in millions per second. Imagine multiplying 10 million pairs of
multi-digit numbers per second. I have a hard enough time myself doing a 3-digit
multiplication in less than a minute.
Computers can store a vast amount of information and retrieve it at extraordinary speeds.
When everything works correctly, this data is as fresh and unblemished by time as when
it was first stored. It can record information about everything (given it has sufficient
storage capacity). While this may not seem to be a great achievement, think about this:
when you last went to the store, how much did you pay for each item you bought?
Computers can store this kind of information a lot better than we can recall it. Also, one
of those CD-ROMs that we see so frequently can store the entire Encyclopedia Brittanica
along with photos. (Please note that if you buy their CD-ROM set, it has more than just
text and photos. So, the set has several CD-ROMs.)
What have computers done for us? Consider the following:
1. Made the world incredibly smaller by facilitating communications.
2. Advanced science and medical discovery more in 10 years than in centuries of
history.
3. Designed cars, roads, cities, clothing, etc.
4. Tested transportation long before the prototypes ever left their studios.
5. Exploded our imaginations with color and virtual reality.
6. Controlled our market-place and caused the “Black Monday” crash.
7. Hinted that a passenger aircraft over Saudi Arabia was an enemy and
recommended firing on it.
8. Opened freedom of speech to areas all over the world via the Internet.
9. Abetted fraud, laundering and gambling.
10.
1 Today (12/4/96), I read plans to make machines “more intelligent”. A quote from Bill Gates, Microsoft
CEO: “If a human assistant works for you over a period of years, your efficiency in working with him gets
dramatically better and he can anticipate your interests and you can use shorthand ways of communicating.
With a computer today, even if you use it for a couple of years, you are basically working with it the exact
same way. It's not learning in the way a human assistant would. On the simplest level, the next generation
of computers would learn the kind of information you like to see. They're going to know how you are
reacting to things, and essentially put together, for example, the kind of newspaper that meets your
interests.” (Investor's Business Daily 3 Dec 96 A8)
The list goes on and on. The computer has done a lot to shape the modern world—some
good and some bad. In all, it has been a great blessing when properly used. What can
computers do for you? Well, hopefully, this text will show you.
1.1WHAT PIECES ARE FOUND IN A COMPUTER?
Jargon
Term Definition
Adapter Most of the time it refers to a card that plugs into the motherboard
adding special capabilities not originally found on the computer. Other
times it refers to tools to convert one connector type to another.
Cables A thick wire that connects the computer to the external device or power.
Cache An interface between the CPU and the memory (RAM and ROM). It
helps the CPU keep running even though the RAM may be too slow. It
does this by keeping a copy of what the processor has read/written.
Card Slot The slots found on the PC motherboard may be one of five types: ISA,
EISA, MCA, VESA & PCI.. Slower adapters (like I/O boards) can be
ISA. But for the best performance, use VESA or PCI for harddrives,
CD-ROMs or Video adapters.
Cards An option (adapter) which is a printed circuit board that plugs into the
motherboard.
CD-ROM A disk made of plastic and aluminum which can store up to 650MB of
data. Usually these disks cannot be written to, instead they often are
used to distribute software from companies.
CPU Central Processing Unit. The “brain” of the computer. It executes
commands which, eventually, we see as a response to our input.
Without the CPU, the computer is nothing.
Disk A storage medium to keep data while the computer is turned off.
DRAM RAM that uses a device called a “capacitor” to store each bit. The
problem with this is the capacitor loses the charge very quickly.
Therefore, the DRAM has to be “refreshed” to keep the data valid. This
is thus far the cheapest RAM.
DVD The next generation CD-ROM which will store 10-20x the current
capacity.
Floppy A disk that has flexible media (the actual material onto which the data is
recorded). The material and flexibility is a lot like that of a cassette tape.
Glidepoint A mouse-replacement that has a little pad that you can use to move the
mouse pointer. Simply glide your finger over the surface and the pointer
will move. To “click”, tap the pad. To “double-click” double-tap the
pad.
Harddisk A medium to store data for the computer while the power is out. It uses
a hard material (typically aluminum).
Keyboard A typewriter-like tool that has keys. Sends letters or commands to the
computer.
Microprocessor
A CPU that composes only one chip. Some CPUs may actually be
several square feet is size; but, the microprocessor is designed to be
100% self-contained in a single chip.
Modem A device that will let your computer talk to other computers through the
telephone line.
Jargon
Monitor The CRT or display that shows the words, graphics, etc., to the user. It
is a critical part of a user’s interface.
Motherboard A printed circuit board that has (at least) slots to connect cards into.
Often, they also include a CPU and memory.
Mouse An input device which has one to three buttons and when you move it, it
causes the arrow in a Windows display to move.
Open
Architecture
The original computer companies hid their secrets from competitors by
keeping their architecture closed (proprietary). IBM made the IBM PC
an open architecture, allowing anyone to make options for it.
Parallel A type of port which transmits and receives several bits of data at a time
(typically 8 bits). Typically used to connect to printers.
Ports Connectors (usually in the back of the computer) which connect to
external devices (e.g. mouse, keyboard, modem, printer, display, etc.)
Power supply A basic component in the computer that converts the outlet power into
power that the computer can use.
Printer An external device that takes commands and data from the computer to
place on paper. There are several types of printers: daisy-wheel, matrix,
laser, thermal, inkjet, and plotter.
RAM “Random Access Memory“. A pool of storage for the CPU. It can be
written to/read from in any order (unlike a VCR tape which is serial—
you have to wind to the place you want). There are several types of
RAM: SRAM, DRAM, EDO-RAM.
ROM “Read Only Memory“. Memory that has imprinted in it data and
programs for the CPU which cannot be erased or written to.
Scanner An external device that is able to optically read in printed material—kind
of like a copier, but it stores the image on the computer instead.
Serial A type of port that transmits only one bit at a time. In order to send a
byte of data, the data has to be “turned on its side” and send out bit by
bit.
SRAM RAM that does not “lose its mind” if not refreshed. This is typically
used in caches. It tends to be much more complicated than DRAM and
thus much more costly.
Surge
protector
A device that will isolate your computer from outlet power problems
(spikes and noise).
Trackball A mouse replacement that is a small box with a ball in the center. You
roll the ball in the direction you want the pointer to go.
Trackpoint A mouse replacement with a little rubber post between the “g” and “h”
keys on some laptop computers. Gently push the post in the direction
you want the mouse pointer to go.
UPS “Uninterruptable Power Supply”. This is a box that is like a surge
protector but will keep you going even if you lose power. You can plug
your computer into. If you have a brown- or black-out, this unit will
keep you running for 3 minutes to an hour (certainly enough time to save
your work and shutdown the computer).