The word computer comes from the Latin word
"computare" which means to
calculate!
In the 19th century the Frenchman Jacquard
developed a weaving machine,
which worked by being programmed with punch
cards. This inspired
Englishman Charles Babbage to use the same
method of programming to
calculate.
Konrad Zuse thought the decimal system wasn't
suited to mechanical
calculations and decided that the Binary
system (0 and 1) would be more
suitable. In 1941 Zuse built the first programmable
calculating machine,
the Z3. The Z3, designed for military purposes,
read from punched tape.
With the shortage of punch tape during the
2nd World War, left over film
was used.
The modern PC evolved from a huge machine
created for the military by
two scientists Mauchley & Eckert. This
calculating machine called ENIAC,
weighed 30 tons and filled a huge room and
used so much electricity it
needed its own generator. These days the
ENIAC would be equal to your
typical handheld simple calculator.
IBM played an important part in the history
of computers. They produced
electronic typewriters and punch card calculators,
and by the 1950s they
had a market in desk calculators. In 1953
IBM introduced the IBM 650,
which became the most popular data processing
system in the world.
The race to be the first to land on the
moon was a boost to developing
new computer technology. In 1969 the the
world's smallest and most
modern computer took the Apollo 11 to the
moon.
The first affordable home use PCs were introduced
in the late 1970s by
Apple, Commodore, Tandy and Texas Instruments.
It wasn't until 1981 that IBM realized the
value of small desktop PCs,
releasing their first, the IBM compatible
PC. IBM compatibles became the
computer industry "standard". IBM bought
an operating system called DOS
(Disk Operating System) off a small company
called Microsoft (now the
largest company in the world); MSDOS (Microsoft
Disk Operating System)
was then installed on all IBM machines.
So 1981 is where the success of personal
computers began, and IBM and
Microsoft were writing the standards.
Introduction
to Computers
There are many different types of computers,
e.g. desktop, handheld,
mainframes, workstation, Apple Macintosh,
laptop and notebooks just to
name a few.
Computers are divided into three main categories:
Mainframes
Large and powerful computers, used by many
people at the same time
connected by terminals. Mainframes provide
a central location for
information.
Mini Computer
Basically these are smaller mainframes.
Micro Computers
Referred to as Personal Computers (PCs).
Computers designed to be used
by a single person at one time. The two
popular types are Apple
Macintosh and IBM Compatible PCs.
The PC and its Components
Let's look at the desktop PC:
There are four main parts of a computer:
Computer
Monitor
Mouse
Keyboard
Computer
The computer is really the main part; it's
the brains of the system.
They come in all sizes and shapes. Towers
and mini towers are tall and
sit beside or under your desk, whereas desktops
are flat and sit on your
desktop often with the monitor resting on
top.
The computer stores all your files and software
in a component called
the Hard Drive, which is also referred to
as the C: drive.
There are many items hidden in the case,
but that could take all day so
I will list them for another day.
Computer components:
Motherboard
- A single circuit board that all other commponents are
either fitted to or attach to.
Central Processing
Unit - The CPU is a single silicon chip. This is the
heart of the actual computer. Note
1
Input/Output card
- Passes data and instructions to external equipment
such as a printer.
Sound card
- processes digital information for sound aand drives external
speakers.
Graphics card
- processes and stores digital information to your monitor
screen for display.
Network card
- Handles the digital traffic via a cable tto and from
another computer.
RAM memory
- (Random Access Memory) extra memory chipss for programs to
use when they run. Basically, with more
room to run, the quicker and
easier things seem to happen.
ROM memory
- Hard wired in a chip is the computer's innitial intelligence
(a program) when the power is first turned
on.
Power supply
- Converts the 240 volts a.c. from your walll socket to the
d.c. voltages all computer circuits require
to operate.
Fans - a lot
of heat is generated by electronic components. In general
one fan is needed to keep the Power Supply
cool and another for the CPU
chip.
Floppy Disk drive
- This reads from and writes to a removablee portable
storage disk (3.5 inch floppy disk).
CD ROM drive
- A laser reader for removable CDs. These ccontain programs
and data. These days a read/write CD ROM
is available so you can
actually make (burn) your own Cds well as
read others. You could burn an
audio CD, for example, that contains songs
and music.
Modem, internal or
external - This is a device that allows your computer
to communicate with another computer over
a telephone line, i.e. to an
Internet Service Provider
(ISP)
for Internet and email access.
Monitor
The monitor is the piece of hardware that
displays the video output of
the computer; it's just like your television
only a much higher
resolution (clearer picture).
Mouse
The mouse allows you to tell the computer
what to do by sending
electronic signals to the computer. For
right handers with a standard
two button mouse, place your index finger
over the left button, your
middle finger over the right button and
rest your palm on the bridge
gripping the sides with thumb and little
fingers. Have a practice at
driving the pointer on the screen.
Mouse procedures:
Pointing
Rolling the mouse on your mouse mat will
make the pointer on your screen
follow your movements. Notice that sometimes
the pointer / cursor
changes as you move across items / icons.
Left click
Position the pointer where you want it,
press and release Left mouse
button once. This "selects" normally. (Sometimes,
depending on settings
or specific area, left click will "action".)
Right click
Position pointer, press and release Right
mouse button once, a "pop up
menu" will appear.
Double click
Position pointer, press and release Left
mouse button twice. Try not to
drag mouse in between clicks. This normally
"actions".
Left dragging
Position pointer, press and hold the Left
mouse button. Drag item then
release button.
Right dragging
Position pointer, press and hold the Right
mouse button. Release button
when ready.
NOTE: The mouse can be quite sensitive so
it may take a little time to
master. If it loses its sensitivity and
you have trouble guiding the
mouse or the pointer doesn't follow smoothly,
it may mean time for a
clean. Simply turn the mouse over, remove
the cover and tip the ball
out. With a cotton bud or tweezers, remove
the dust buildup from the
rollers. Then put it back together and test
the operation.
Keyboard
This is a typewriter and a calculator combined
with other extra keys.
You communicate with the computer using
the keyboard, as well as the
mouse. Position it where you feel comfortable.
The keyboard has legs
underneath at the back, so if you wish to
adjust the slope, turn it over
and pop the legs out or fold them back for
preferred position. The extra
(12) keys located at the top of the keyboard
are function keys (F1, F2,
etc.) There may also be several specialty
keys either side of the space
bar at the front or bottom of the keyboard.
The function of some of the more common keys:
Enter
Sometimes called the Return key. Basically
when the Enter key is
pressed, the computer accepts information
that you are supplying and
takes the appropriate action. For instance,
when typing text, pressing
the Enter key will cause the Entry Cursor
to go to the start of the next
line. The computer then waits for your next
entry.
F1
(A function key example) In Windows, pressing
the F1 key displays the
main help file.
Esc
This generally cancels a command or action.
Shift and Caps Lock
Shift switches between upper and lowercase
letters of alphabet keys or
changes the output of a key to the top symbol,
but only while the key is
pressed and held down. A light will come
on in the upper right area of
the keyboard to indicate Caps Lock is ON.
Ctrl
Control key is used together with other
keys for specific commands.
Press the Ctrl key and hold while then pressing
another key and then let
both go. Ctrl key operations depend on the
program being run at the time.
Tab
Moves the Entry cursor to the right a set
number of spaces when typing
text in a document.
Page up and Page down
Moves the cursor a whole screen or page
up or down.
Home
Moves cursor to start of the line or the
beginning of a document.
End
Moves cursor to end of the line or the end
of a document.
Delete
Deletes characters to the right of the cursor,
and can delete
highlighted blocks of characters.
....................................................................
Note 1 -- The CPU is the computer. As a person's brain is that person, so the CPU is the computer.
The brain uses the body as input by sight, sound and feeling and output such as speech and movement.
The CPU has external circuits for input by the mouse, keyboard, modem etc. It has output circuits for sound and the monitor and needs external memory.
The person has external memory such as a library and the memory of other people.
The CPU has its own language which is used by all the operating systems installed. (Ed.)
Note 2 -- The 'Insert' key toggles between inserting characters into text and overwriting text. (Ed.)
................................................................................
Floppy Disks
What is formatting?
To format a floppy disk:
CD-ROM
To use the CD-ROM drive:
Modem
Printers
Software
Hardware
Operating system
Let's get started
Desktop
My Computer
Network Neighborhood
Recycle Bin
Taskbar
Start button
Launch bar
Clock/Date
Icons
To start a program
Scrolling
Minimize, Restore and Closing a window
Minimize
Restore
Exit
Help
What's this ? Help button
Floppy disks hold data that is to be transferred to another computer, and also for keeping a backup copy of data. To 'write protect' a floppy disk so data cannot be written over, simply turn the disk over and slide
the little black tab on the left side. An open window means it is write
protected and no window means you can write to the disk.
The floppy drive on the computer is called the 'A' drive. If you have a
second floppy disk drive installed it would be called the 'B' drive but
this is very rare. In Windows you will recognize the drive by the name
A:\ when looking at your drive list.
A floppy disk hold 1.44 megabytes of data, which is about 500 standard
A4 pages of text.
To insert a floppy disk into the drive, insert with the label side up
and the metal slide end in first.
Each floppy disk (as well as any hard drive) must be formatted to hold data, Formatting deletes everything on the disk. If you see 'bad sector' errors in the brief summary after a disk is formatted, throw it away.
Although bad sectors on a disk are flagged as 'not to be used by the
computer', the reliability of the disk is suspect. If you still use the
disk you could risk losing your work if other sectors fail.
1. Insert disk.
2. Double click on 'My Computer' on the desktop.
3. Right click on the A: drive.
4. Choose 'Format' from the popup file menu.
5. Select 1.44Mb and full format check box and other selections as you need.
6. Click the Start button, or press the Enter key.
Note; Never eject a floppy disk when the light near the floppy door is
'on'; you may damage disk and drive. Be careful you don't select C:
drive when formatting a 3½ floppy disk (A: drive), you will lose
everything on your computer (the primary hard drive is C:).
The CD-ROM drive is usually the D: or E:drive. It holds about 600-700 megabytes of data. CD-ROM (Compact Disc Read Only Memory) can only be
read and not written to.
If your comuter has a sound card and speakers, you can play music CDs on
your computer, just like a stereo.
Open drawer.
Place disk, printed side face up.
Close drawer.
Some CDs start automatically, else, On your desktop, double click on My Computer icon (top left). Then access D or E drive as normal by double clicking on the D or E drive icon. It will probably have a small picture icon that looks like a
Compact Disk.
A modem enables you to send and receive information to and from other computers across the phone lines such as your Internet Service Provider
(ISP). Modems can be internal or external of your computer (inside or
outside of the computer box). A fax modem allows you to send and receive
faxes through your computer as well as computer digital data.
A printer allows you to transfer documents from the computer to the printer to print onto paper.
There are three main types of printer:
Laser printers: Fast producing high quality output. Same technology used
as photocopiers.
Ink Jet printers: Slower, although a quality output. Sprays ink at a
sheet of paper.
Dot matrix printers: Just about out of date; low quality output. Strikes
pins against a ribbon to make dots.
Software is a name for programs that run on a computer. You will in time hear of shareware and freeware software. These usually come on a demo
disk, PC magazines or downloaded off the Internet.
Shareware is a test before you buy software, usually a 30 day free trial
then you need to register with a small payment while freeware is 100%
free, although most require you to register but do not ask for a payment.
Hardware is a term for the physical equipment you can touch, e.g. mouse, keyboard, printer, etc. These hardware items are categorized as input and output devices.
Input devices include: Mouse, keyboard, scanner, disks, modem, microphone, joystick.
Output devices include: Printer, disks, monitor, speakers, modem.
All computers have some type of operating system. The operating system controls the functions of the computer. They are designed to manage the hardware and software on the computer system.
They are the link between you and the computer.
Examples of operating systems include Windows 95/98/NT, DOS, OS/2, Unix,
Linux.
Note: If you happen to get a prompt C:\ it means you are in MS-DOS;
simply type win to get to the Windows operating system.
To turn the computer on
Note: Remove any floppies from the A:\ drive and any CD-ROMs before
starting computer.
There are usually two power buttons; one is located on the monitor and
the other on the case. Turn both on, you should hear strange noises and
see words on the screen; these are normal self-checks. This process is
called "booting". A background with small pictures should appear. This
is called the desktop.
The desktop is your main working area. It has many features to navigate you around your computer. Components of the desktop are described below.
Lists the items that are available on your computer.
Available if you are in a networked environment, which allows you to connect with other computers.
Holds deleted files until you permanently remove them. When recycle bin has paper appearing in the icon, it means there are files in it.
<>Inbox
An email program.
Shows programs that are opened and loaded into memory (RAM).
Access the menu system and also to shutdown the computer.
Shows which programs started on startup.
Shows time and when you run mouse over it, it shows the date.
Are shortcuts to programs on your computer. Double click to open program.
Click Start.
A popup menu appears; run your mouse up the menu; the arrows indicate a
sub menu. A coloured bar will follow you to guide you.
Go to Programs. Another sub menu appears.
Go to Accessories. Yes, another menu, this is a way to access programs on your computer.
When you find the program you want, simply left click on it.
When moving to sub-menus always move horizontally then vertically.
Exercise
Would you like to play a game? If you can find Solitaire, you can!
Note: Windows Explorer is found under Programs; this is your main menu
on your computer.
A scroll bar will appear on the screen if there is more information than the screen can show. If this happens you need to use the scroll bar on
the right side of the page. Simply hold mouse button on the down arrow
for the page to scroll.
To increase or decrease the size of a window use the boxes at the upper right of the screen:
Suspends the program. Click on name of the document in taskbar to get back and restart it.
Full screen mode
Closes window and deletes the program from memory, exits.
The help file is very handy; all programs come with a help file. If you need help or want more information on a subject, use this help file to find your answer,
Click Start. Click Help.
You will come across this question mark at the top of some pages. This is the "What's this" icon.
Click on the question mark.
Mouse pointer should change to the help pointer.
Click where you want to know more about a subject.