COMP1 REVIEWER 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. A BRIEF COMPUTER HISTORY 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. You learned earlier that a computer has electronic and mechanical parts known as hardware. 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. 4 . A Microphone -- The microphone is usually used for voice input into the computer. 5. A Digital Camer -- The digital camera allows you to take pictures that you can input into your 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. Output Devices An output device is any hardware component that gives information to the user. 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 3.A Speaker -- Sound is the type of output you will get from a speaker. COMPUTER SOFTWARE The computer will not work without software. Software also call programs are the instructions that tell the computer what to do and how o do it. The two main categories of software are system software and application software. The system software also called the operating system (OS) actually runs the computer. This software controls all the operations of the computer and its devices. All computers use system software and without the system software the application software will not work. The most common OS on a PC is the Windows operating system and for the Mac computer it would be the Mac operating system. Application software is a program that allows users to a specific task on the computer. There are a number of different types of application software available to do many of the tasks we do daily. Four examples of common application software and what they are used for are: Word Processing Application: One word processing program is Microsoft Word. This program allows you to type letters, assignments and do any other written activity on the computer. Spreadsheet Application: Microsoft Excel is an example of a spreadsheet program. One can use this program to create charts and do calculations. E-mail Application: Outlook Express is an e-mail program that allows you to receive and send e-mails. Internet Application: Internet Explorer is a program that allows you to get connected to the Internet and look at Web sites like the one you are reading now. It is important to note that when you buy a computer the computer comes with the operating system and some software already installed. You may have to buy more software and install them on the computer. Install means to load the software onto the hard disk of the computer so that you can run or use the software. Like any other equipment the computer needs to be cared for; let us discuss how we should go about caring for our computer. Computer Hardware Continued THE SYSTEM UNIT The system unit, like the one above is the case that contains all the electronic components of any computer system. The electronic components are considered internal hardware seeing that they are inside the system unit and you cannot see when you look at the computer. These components inside the system unit are what process the data and really makes the computer work. Internal components are as follow: Power Supply: The power supply converts electricity into the current works for the computer. When the computer is turned on the power supply allows converted electricity to travel to other components inside the computer. Motherboard: The motherboard is the circuit board that holds the main internal components of the computer together. On the motherboard there are three major cards; sound card that operates the sound, the video card that handles the graphics that you see on the monitor and the modem card which allows computers to communicate with each other. Also on the motherboard is the Central Processing Unit (CPU), processor or brain of the computer. The CPU controls information and tells the other components inside the computer what to do. RAM & ROM: RAM stands for random access memory. This memory holds theinformation you are working with while the computer is turned on. Once you turn the computer off all the information that was in RAM will be gone. ROM stands for read only memory. This memory holds information that you can only read, but not erase. Information in ROM is built in and is always there even when the computer is turned off. Disk Drives: The disk drive is the device that reads information that is on disk. Generally speaking most computers have three disk drives; hard disk drive, floppy disk drive and CD-Rom drive. However, there computers that have DVD-Rom drive. While the hard disk is hidden inside the computer the floppy and CD-Rom drives are accessible from the front of the system unit.
Posted on: Mon, 28 Jul 2014 14:37:09 +0000
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