Many people believe that knowing how to use a computer, is one of the basic skills needed to succeed in the workplace. In order to use the computer it is necessary to understand how the computer works.
Computer hardware is made up of the equipment used to make up you computer unit. These parts include your monitor, System Unit(CPU,Mpotherboard,Ram,Hard Discetc), keyboard, mouse, printer, and modem.
The computer is an electronic machine that performs the following four general operations:
The input hardware allows you to enter data into the computer. The primary devices used are the keyboard and mouse.
Keyboard - The keyboard looks like the typewriter. A numeric keypad is located to the right of the keyboard. Numeric keys have the same placement as a 10-key calculator, which allow the operator to enter data rapidly.
Mouse - The mouse is a device that allows you to control the movement of the insertion point on the screen. There are other input devices, such as touch screen, joystick, modem, scanner, and voice recognition systems.
The central processing unit or (CPU) is the "brain" of your computer. It contains the electronic circuits that cause the computer to follow instructions from ROM (read only memory) or from a program in RAM (random access memory). By following these instructions information is processed. The CPU contains three parts.
1. Arithmetic Logic Unit - ALU is where the "intelligence" of the computer is located. It can add and compare numbers. To multiply 2 x 4 the computer would add 2 + 2 + 2 + 2. The ALU makes decisions by determining if a number is greater, less, or equal to the other number. Processing is completed in nanoseconds, which is a billionth of a second.
2. Memory(Primary Memory) - Two types of memory contained on a chip are RAM (Random Access Memory) or ROM (Read Only Memory). ROM memory has been installed on your computer by the manufacturer and can not be altered. ROM is the memory that determines all the basic functions of the operation of your machine, such as startup, shut down, and placing a character on the screen. RAM is temporary memory, which displays the information you are working on. RAM remembers what you see on your screen while you are working. Today's applications required large amounts of temporary memory, which may require you to upgrade and add more RAM memory.
3. Control Unit - This is the part of the unit, which directs information to the proper places in your computer, such as calculation of information by the ALU unit or to store and print material.
Output devices such as a monitor or printer make information you input available for you to view or use.
A monitor's front is called a screen with a cathode ray tube (CRT) attached to the screen. Portable computers use a (LCD) liquid crystal display. Today's super video graphics array (SVGA) monitors display 256 sharp and clear colors.
Printers used with computers fall into two categories, impact or nonimpact.
Auxiliary storage devices, also called secondary storage devices, are used to store instructions and data when they are not being used in memory. Two types of auxiliary storage more often used on personal computers are floppy disks and hard disks. Also, CD-ROM drives are common.
Floppy Disks - A floppy disk is a circular piece of oxide-coated plastic that stores data as magnetic spots.
Hard Drive - Much like a floppy, the hard disk located inside the computer case is made of a stack of rotating disks, called platters. Data is recorded on a series of tracks that have been divided into sectors. Most computers have one hard drive, located inside the computer case. If a computer has one hard drive, it is called drive C. If a computer has additional hard drives, they are called drives D, E, and so on. A hard drive stores your programs. When you buy a new program, you must install the program files to your hard drive before you can use the program. A hard drive stores your data files such as documents spreadsheets, and graphics.
CD-ROM Storage - Since each CD-ROM can store 600 million bytes of data or 300,000 pages of text, they are today's answer to make you computer feel like a machine twice its size. Because of its external storage, you can use your machine to access an encyclopedia, games, graphics, and a variety of sources that use large amounts of memory.
Bits and Bytes
A computer stores data in units called bits and bytes. Computer chips called integrated circuits have one of two states, off or on. Therefore, a system was developed that used only two numbers, 0 and 1. Zero representing off and 1 representing on. You can think of this as a sort of light switch. Each switch is called a bit.
Computer productivity is determined by programs which are step by step instructions telling the computer how to process data. Software can be divided into two groups, system and application.
System software - The operation of your computer is controlled by system software. As you boot the computer, the system software is stored in the computer's memory which instructs the computer to load, store, and execute an application.
Examples of system software are Windows Xp and Windows 7 which use a graphical user interface (GUI) that provides visual clues (icons) to help the user. DOS, another disk operating system, is (CUI) text based and not user friendly.
Application Software:-Professional programmers write a variety of application software to satisfy needs of the public who wants to perform specific tasks on their computers. The basic types of application software are word processing, database, spreadsheet, desktop publishing, and communication.
Computers can be connected to multimedia, such as sound graphics, photographs, and video equipment to manipulate, input, and generate output, but special software is required.
Computers are rapidly changing and changing the world we live in. We used to talk about the changes made in one generation. Now we see changes from year to year. However, all computers have several parts in common:
" input devices which allow data and commands to be entered into the computer
" a means of storing commands and data
" a central processing unit which controls the processing
" a means of returning the processed information in the form of output
In general, a computer is a machine which accepts information, processes it and returns new information as output.