The computer as we know it today had its beginning with a 19th century English mathematics professor name Charles Babbage.
He designed the Analytical Engine and it was this design that the basic framework of the computers of today are based on.
Generally speaking, computers can be classified into three generations. Each generation lasted for a certain period of
time,and each gave us either a new and improved computer or an improvement to the existing computer.
First generation: 1937 – 1946 - In 1937 the first electronic digital computer was built by Dr. John V. Atanasoff and Clifford Berry. It was called the Atanasoff-Berry Computer (ABC). In 1943 an electronic computer name the Colossus was built for the military. Other developments continued until in 1946 the first general– purpose digital computer, the Electronic Numerical Integrator and Computer (ENIAC) was built. It is said that this computer weighed 30 tons, and had 18,000 vacuum tubes which was used for processing. When this computer was turned on for the first time lights dim in sections of Philadelphia. Computers of this generation could only perform single task, and they had no operating system.
Second generation: 1947 – 1962 - This generation of computers used transistors instead of vacuum tubes which were more reliable. In 1951 the first computer for commercial use was introduced to the public; the Universal Automatic Computer (UNIVAC 1). In 1953 the International Business Machine (IBM) 650 and 700 series computers made their mark in the computer world. During this generation of computers over 100 computer programming languages were developed, computers had memory and operating systems. Storage media such as tape and disk were in use also were printers for output.
Third generation: 1963 - present - The invention of integrated circuit brought us the third generation of computers. With this invention computers became smaller, more powerful more reliable and they are able to run many different programs at the same time. In1980 Microsoft Disk Operating System (MS-Dos) was born and in 1981 IBM introduced the personal computer (PC) for home and office use. Three years later Apple gave us the Macintosh computer with its icon driven interface and the 90s gave us Windows operating system.
As a result of the various improvements to the development of the computer we have seen the computer being used in all areas of life. It is a very useful tool that will continue to experience new development as time passes.
COMPUTER FUNDAMENTALS
A computer is an electronic machine that accepts data, stores and processes data into information. The computer is able to work because there are instructions in its memory directing it.
The parts of the computer that you can see and touch, such as the keyboard, monitor and the mouse are called hardware. The instructions that direct the computer are called software or computer program.
Data which is raw facts that you the user enter into the computer is called input. This includes; words, numbers, sound and pictures. When the data is entered into the computer, the computer processes the data to produce information which is output. For example, you enter 2+2 into the computer as data, the computer processes it and the result is 4 which is information.
Computers are usually categories into three general categories:
1.Supercomputer – The fastest, largest, most powerful and most expensive computer.
2.Mainframe Computer – This is a little smaller and less powerful than the supercomputer, but, like the supercomputer it is also expensive.
3.Personal Computer (PC)- This is the computer that most people use in their daily lives. This computer is much smaller, less powerful and less expensive than the supercomputer and the mainframe computer. There are two main types of personal computers. Macintosh (Macs) and the PC compatibles (PC). The main differences between the two are the operating systems and the processor they use. This category of computer has two additional types of computers. These are mobile computer and handheld computer. The most popular type of mobile computer is the notebook or laptop computer, and the handheld computer is a very small PC that you can hold in your hand.
It is important to note that, any computer; regardless of its size has an input device, output device and a system unit.
COMPUTER HARDWARES
Hardware also includes input devices, output devices, system unit, storage devices and
communication devices. Without these components we would not be able to use the computer.
Input Devices - An input device is any hardware component that allows you the user to enter data into the computer.
There are many input devices. Six of the most widely used input devices are:
1. A keyboard -- You use the keyboard to type letters,numbers,and symbols into the computer.
2. A Mouse
--The mouse is a pointing device that has a pointer
that changes into different shapes as you use the mouse.
You click the mouse by pressing and releasing the button.
This action allows you to enter data when using a mouse.
3. A Scanner -- This input device copies from paper into your computer. that changes into different shapes as you use the mouse.
You click the mouse by pressing and releasing the button.
This action allows you to enter data when using a mouse.
4 . A Microphone -- The microphone is usually used for voice input into the computer.
6. A PC Video Camera -- The PC video camera allows you take both video
and still images that you can input onto your computer.
and still images that you can input onto your computer.
Three commonly used output devices are as follow:
1. A Monitor -- This output device displays your information on a screen,
2. A Printer -- This output device prints information on paper.
This type of printed output is called a hard copy
This type of printed output is called a hard copy
3.A Speaker -- Sound is the type of output you will get from a speaker.
The other main computer hardware we need to examine is the system unit
it will continue sooon..........
nokia E51 image
laptops image
tower computer image