August 2001
Computing for the Bewildered. By Bill Hayles
Hello again.
I've been asked:
"What are Windows?"
The answer is quite simple. Windows are panels of transparent
material, usually glass, designed to let light into a room.
What I think the question was meant to be is:
"What is Windows".
That's such a complex topic that I'm going to take two articles to
answer it. This month, I'll explain what the major components of a
computer are, and what they do. Next month, I'll explain how they are
controlled by Windows. I am talking solely about PCs. Not all of what
follows applies to Apple Macs, Archimedes or other esoteric products.
The heart of any computer is the CPU - the Central Processing Unit.
Usually made by Intel, but increasingly also by AMD, this is the
"brains" of the machine. It is the component that works out what to do
and how to do it. More or less everything else on the computer is
concerned with inputting or outputting data from the CPU.
RAM (Random Access Memory) is where the CPU keeps the data that it's
working with at any given time. It's electronic and very fast.
However, all the contents of RAM are lost when the computer is turned
off. For this reason, the CPU needs to be able to store data. The main
facility for this is the hard disk.
The term "hard disk" is very misleading. A better term would be "fixed
disk" or "internal disk", as the hard disk is located inside the
computer. It can be written to, and read from, by the CPU and stores vast
quantities of data, in the form of individual files. Many of these
files are part of the software installed on your computer, such as
Outlook Express or Microsoft Word, others contain the data that you,
yourself have created, such as e-mails you have sent and documents you
have written. A third category are the (usually temporary) files that
the CPU creates as it goes about its business. This data is permanent,
in the sense that it can stay on the hard disk for years. However, it
is very easily erasable - all too easily. Anybody who has used a
computer for any length of time will have stories about accidentally
deleting something important - I know I have!
Other storage media are the floppy disk and the CD (or, nowadays, DVD).
Although declining in importance, the floppy disk is still notable as a
quick and easy method of transferring data. More correctly called a
removable disk, this is a small plastic square (!) containing magnetic
media, which can be read from and written to like a hard disk, but fits
into a slot in the front of the computer and can be inserted and
removed. In comparison with a hard disk, it has very little capacity
and is very slow. CDs are frequently used to transfer software programs
onto your computer, and are usually read only (input) devices, although
CD writers and re-writers, which use special blank CDs which can be
used in a similar way to a floppy disk are becoming increasingly common.
Disks are called "input / output" devices. There are many others. You
need to be able to communicate with the CPU. You do this by means of
the keyboard and the mouse. These are both input devices. You see
what is going on by looking at the monitor, an output device,
controlled by a video card. Just as an aside, the CPU itself doesn't
need the monitor. A computer will work quite happily with the monitor
turned off, or even not connected, provided it can somehow be given the
correct instructions by its operator.
The video system (card) is currently the area of computer technology
which is seeing the most rapid advances, and modern cards can accept
input from digital cameras and can output to TVs and other devices.
A printer is also an output device, whereas a scanner is
an input device. Modern computers have sound cards, which can
work as both input (through microphones, CD or "line" input) and output
(through loudspeakers or headphones). Sound is another area of rapid
advance.
If your computer is through a LAN (Local Area Network), it will have a
network card by which your CPU talks to others in the area. It will
almost certainly have a modem, either built in, or accessed externally
through a cable. This will connect your little computer to the
millions of others that collectively make up The Internet. Whilst on
line, your computer is a small part of the largest network in the
world!
Further devices you may come across are tape drives, normally used for
backing up the data on the hard disk, and joysticks for use with
certain games
As you can see, there are a great many devices that can be connected to
a PC and made to work. To control them, you need an operating system.
The operating system used on eight out of ten modern PCs in Spain, and
nine out of ten worldwide, is Microsoft Windows in one of its recent flavours
(95, 98, Millennium, 2000, NT, XP and others). Nowadays, its only real
competitor is the Linux system (which is especially popular in Spain)
I use Linux, but seeing as how I'm in the minority, next month we'll
look at Windows, what it is and, just as importantly, what it isn't,
and how it controls a computer.
That's it for another month. My Saturday morning classes will re-start
on Saturday, 15th September at 1030 at The Oasis Centre. The sessions
are intended for absolute beginners, who don't know the difference
between the World Wide Web and a spider's web. If you know absolutely
nothing about computers and the Internet, but want to, these sessions
are aimed at you. Details will be on the Internet at
http://www.billnot.com, but seeing as how you probably don't know how
to get on line, I'm intending to leave an introductory sheet at the
CopiShop. In any case, you're welcome simply to turn up. It's worth
it for Ann's tea and biscuits alone!
If you have a question you'd like me to answer in the column, please
e-mail it to questions@billnot.com, If you don't have e-mail, you can
always leave your question at the CopiShop. However, I can't guarantee
to answer questions personally.
If you have been, thanks for reading this.