COMPUTER COMPONENTS

Component devices that are the building blocks of personal computers. These are typically installed into a computer case, or attached to it by a cable or through a port. In the latter case, they are also referred to as peripherals.

Storage Devices: 

Primary Storage

 RAM

 ROM

 Secondary Storage

Input Devices 

Output Devices

  

CLASSIFICATION OF COMPUTER

 MICROCOMPUTERS

THESE COMPUTERS USE A MICROPROCESSOR CHIP AND THIS CHIP IS USED INSTEAD OF CPU MEANS THAT THIS MICROPROCESSOR CHIP WORKS AS A CPU.THESE COMPUTERS ARE ALSO CALLED PERSONAL COMPUTERS. TWO MAJOR TYPES OF THESE COMPUTERS ARE LAPTOP OR DESKTOP COMPUTERS. ONLY ONE USER USES THESE COMPUTERS AT TIME THAT'S WHY THEY ARE ALSO KNOWN AS PERSONAL COMPUTERS

MINICOMPUTERS

THESE ARE POWERFUL COMPUTER. THESE COMPUTERS COME INTO EXISTENCE IN 1960S AT THAT TIME MAINFRAME COMPUTER WAS VERY COSTLY. MINI COMPUTERS WERE AVAILABLE IN CHEAP PRICES, SO USERS START USING IT.

MAINFRAME COMPUTER

IT AS A VERY POWERFUL AND LARGE COMPUTER. YOU CAN GET IDEA OF ITS POWER AS IT CAN HANDLE PROCESSING OF MANY USERS AT A TIME.TERMINALS ARE USED TO CONNECT A USER TO THIS COMPUTER AND USERS SUBMIT THERE TASK THROUGH MAINFRAME. TERMINAL IS A DEVICE WHICH HAS KEYBOARD AND A SCREEN. BY USING TERMINAL USERS PUT INPUTS INTO THE COMPUTER AND GET THE OUTPUT THROUGH SCREEN.

 SUPER COMPUTERS

AS THE NAME "SUPER COMPUTER" SPECIFIES THAT THESE ARE MOST POWERFUL COMPUTERS EVEN THAN MAINFRAME. ACTUALLY, WHEN WE OPTIMIZE A MAINFRAME COMPUTER THEN WE GET SUPER COMPUTER.

WORKSTATIONS

WORKSTATIONS ARE COMPUTERS THAT ARE INTENDED TO SERVE ONE USER AND MAY CONTAIN SPECIAL HARDWARE ENHANCEMENTS NOT FOUND ON A PERSONAL COMPUTER.

COMPUTER HISTORY AND GENERATION

 COMPUTER HISTORY

 

The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued with the same meaning until the middle of the 20th century. From the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations.
 

COMPUTER GENERATIONS

FIRST GENERATION (1940-1956) VACUUM TUBES

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.
First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts.
The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.

 

 

 SECOND GENERATION (1956-1963) TRANSISTORS

Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.
Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

THIRD GENERATION (1964-1971) INTEGRATED CIRCUITS

The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.
Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.
   

 

  FOURTH GENERATION (1971-PRESENT) MICROPROCESSORS

The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer from the central processing unit and memory to input/output controls on a single chip.
In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.
As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

FIFTH GENERATION (PRESENT AND BEYOND) ARTIFICIAL INTELLIGENCE

Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

WHAT IS COMPUTER NETWORK ?

Networks are collections of computers, software, and hardware that are all connected to help their users work together. A network connects computers by means of cabling systems, specialized software, and devices that manage data traffic. A network enables users to share files and resources, such as printers, as well as send messages electronically (e-mail) to each other.
Computer networks fall into two main types: client/server networks and peer-to-peer networks. A client/server network uses one or more dedicated machines (the server) to share the files, printers, and applications. A peer-to-peer network allows any user to share files with any other user and doesn’t require a central, dedicated server.
The most common networks are Local Area Networks or LANs for short. A LAN connects computers within a single geographical location, such as one office building, office suite, or home. By contrast, Wide Area Networks (WANs) span different cities or even countries, using phone lines or satellite links.
Networks are often categorized in other ways, too. You can refer to a network by what sort of circuit boards the computers use to link to each other – Ethernet and Token-Ring are the most popular choices. You can also refer to a network by how it packages data for transmission across the cable, with terms such as TCP/IP (Transmission Control Protocol/Internet Protocol) and IPX/SPX (Internet Package eXchnage/Sequenced Package eXchange).

HOW IS COMPUTER WORK ?

 

Computer Basics

To accomplish a task using a computer, you need a combination of hardware, software, and input.

Hardware consists of devices, like the computer itself, the monitor, keyboard, printer, mouse and speakers. Inside your computer there are more bits of hardware, including the motherboard, where you would find the main processing chips that make up the central processing unit (CPU). The hardware processes the commands it receives from the software, and performs tasks or calculations.

Software is the name given to the programs that you install on the computer to perform certain types of activities. There is operating system software, such as the Apple OS for a Macintosh, or Windows 95 or Windows 98 for a PC. There is also application software, like the games we play or the tools we use to compose letters or do math problems.

How They Work Together

First, you provide input when you turn on the computer. Then the system software tells the CPU to start up certain programs and to turn on some hardware devices so that they are ready for more input from you. This whole process is called booting up.

The next step happens when you choose a program you want to use. You click on the icon or enter a command to start the program. Let's use the example of an Internet browser. Once the program has started, it is ready for your instructions. You either enter an address (called a URL, which stands for Uniform Resource Locator), or click on an address you've saved already. In either case, the computer now knows what you want it to do. The browser software then goes out to find that address, starting up other hardware devices, such as a modem, when it needs them. If it is able to find the correct address, the browser will then tell your computer to send the information from the web page over the phone wire or cable to your computer. Eventually, you see the web site you were looking for.

 If you decide you want to print the page, you click on the printer icon. Again, you have provided input to tell the computer what to do. The browser software determines whether you have a printer attached to your computer, and whether it is turned on. It may remind you to turn on the printer, then send the information about the web page from your computer over the cable to the printer, where it is printed out.

WHAT IS COMPUTER SYSTEM ?

A complete, working computer. Computer systems will include the computer along with any software and peripheral devices that are necessary to make the computer function. Every computer system, for example, requires anoperating system.