INTRODUCTION TO COMPUTERS

Unit 1: Introduction to Computer

LEARNING OBJECTIVES

1. Importance and Application of Computer
2. Generation of computers
3. Personal Computer and its parts
4. Importance and Applications of Computer

COMPUTER

A computer is an electronic device that process, stores and outputs data at high speeds. It is used for handling larger quantity of data and for performing mathematical operations very rapidly. A computer has no capacity to think and will perform tasks only when programs have been formulated.

The Basic Advantages of a Computer

Speed - Computer speeds are measured in Microseconds, Nanoseconds and even in Pico seconds.

Versatility- A Computer is capable of performing almost every task.

Diligence - A Computer is free from tiredness and lack of concentration.

Accuracy- The computer is 100% accurate and capable to perform arithmetical calculation and logical operations with the same accuracy.

Application of Computers

Computers have their application or utility everywhere. We find their applications in almost every sphere of life–particularly in fields where computations are required to be done at a very fast speed and where data is so complicated that the human brain finds it difficult to cope up with.

As you must be aware, computer now-a-days are being used almost in every department to do the work at a greater speed and accuracy. They can keep the record of all the employees and prepare their pay bill in a matter of minutes every month. They can keep automatic checks on the stock of a particular

item. Some of the prominent areas of computer applications are: Tourism, Hotels, Railways, Airline, Architects, Banks, Industry, Transportation, Education, Entertainment etc.

Generation of Computers

It used to be quite popular to refer to computers as belonging to one of several "generations" of computer. These generations are:-

The First Generation (1940-1956): 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. 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.

The Second Generation (1956-1963): 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.

The Third Generation (1964-1971): 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.

The Fourth Generation (1971-Present): 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. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

The Fifth Generation (Present and Beyond): 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.

Personal Computer and its parts

A computer system comprises hardware and software. Hardware is the physical medium whereas Software consists of computer programs.

The physical components of the computer which are located inside the cabinet are called Hardware.

Software is the program that enables a computer to perform a specific task, as opposed to the physical components of the system.

Hardware part of computer comprises Input, Output and Processing devices.

Hardware

The physical components of computer technology which are used as structural and operational equipment that may be outside or inside the computer and which can be touched by anyone are known as hardware. Some computers parts are explained below:

Keyboard: A keyboard is used mainly for typing text into your computer. Like the keyboard on a typewriter, it has keys for letters and numbers, but it also has special keys like Function keys, Numeric keypad and Navigation keys.

Mouse: A mouse is a small device used to point to and select items on your computer screen. Although mice come in many shapes, the typical mouse does look a bit like an actual mouse. It's small, oblong, and connected to the system unit by a long wire that resembles a tail. Some newer mice are wireless.

CPU: The Central Processing Unit (CPU) is responsible for interpreting and executing most of the commands from the computer's hardware and software. The CPU could be

considered the "brains" of the computer. The CPU is Also Known As: processor, computer processor, microprocessor, central processor, "the brains of the computer".

Monitor: A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures. There are two basic types of monitors: CRT (cathode ray tube) monitors and LCD (liquid crystal display) monitors. Both types produce sharp images, but LCD monitors have the advantage of being much thinner and lighter. CRT monitors, however, are generally more affordable.

Motherboard: The motherboard serves to connect all of the parts of a computer together. The CPU, memory, hard drives, optical drives, video card, sound card and other ports and expansion cards all connect to the motherboard directly or via cables. The motherboard can be thought of as the "back bone" of the computer.

Memory: In computing, memory refers to the physical devices used to store programs (sequences of instructions) or data on a temporary or permanent basis for use in a computer or other digital electronic device. The term primary memory is used for the information in physical systems which are fast (i.e. RAM), as a distinction from secondary memory, which are physical devices for program and data storage which are slow to access but offer higher memory capacity.

Hard Disk: Your computer's hard disk drive stores information on a hard disk, a rigid platter or stack of platters with a magnetic surface. Because hard disks can hold massive amounts of information, they usually serve as your computer's primary means of storage, holding almost all of your programs and files. The hard disk drive is normally located inside the system unit.

Floppy Disk and Floppy Disk Drive: Floppy disk drives store information on floppy disks, also called floppies or diskettes. Compared to CDs and DVDs, floppy disks can store only a small amount of data. They also retrieve information more slowly and are more prone to damage. For these reasons, floppy disk drives are less popular than they used to be, although some computers still include them.

Pen Drive: A pen drive is a portable Universal Serial Bus (USB) flash memory device for storing and transferring audio, video, and data files from a computer. As long as the desktop or laptop has a USB port, and the pen drive is compatible with the operating system, it should be easy to move the data from the hard drive to the device — and to another computer — in a matter of minutes.

Computer Power Supply and Cabinet: A power supply unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer. Modern personal computers universally use a switched-mode power supply. Some power supplies have a manual selector for input voltage, while others automatically adapt to the supply voltage.

Computer cabinets are fitted with doors and side panels (which may or may not be removable). Cabinets enclose a rack, which is a frame that provides a means for mounting electronic equipment. Cabinets come in a variety of styles, colors, and many contain baffles, fans, and other features.

CD-ROM and DVD drives: Nearly all computers today come equipped with a CD or DVD drive, usually located on the front of the system unit. CD drives use lasers to read (retrieve) data from a CD, and many CD drives can also write (record) data onto CDs. If you have a recordable disk drive, you can store copies of your files on blank CDs. You can also use a CD drive to play music CDs on your computer.

DVD drives can do everything that CD drives can, plus read DVDs. If you have a DVD drive, you can watch movies on your computer. Many DVD drives can record data onto blank DVDs.

Serial and Parallel Interfaces: Serial ports represent the first interfaces to allow computers to exchange information with the "outside world". The term serial refers to data sent via a single wire: the bits are sent one after the other.

Parallel data transmission involves sending data simultaneously on several channels (wires). The parallel ports on personal computers can be used to send 8 bits (one octet) simultaneously via 8 wires.

Printer: In computers, a printer is a device that accepts text and graphic output from a computer and transfers the information to paper, usually to standard size sheets of paper. Printers vary in size, speed, sophistication, and cost. In general, more expensive printers are used for higher-resolution color printing.

The dot-matrix printer was a popular low-cost personal computer printer. It's an impact printer that strikes the paper a line at a time. The best-known non-impact printers are the inkjet printer, of which several makes of low-cost color printers are an example, and the laser printer.

Modem: To connect your computer to the Internet, you need a modem. A modem is a device that sends and receives computer information over a telephone line or high-speed cable. Modems are sometimes built into the system unit, but higher-speed modems are usually separate components.

Tape drives: A device, like a tape recorder, that reads data from and writes it onto a tape. Tape drives have data capacities of anywhere from a few hundred kilobytes to several gigabytes. Their transfer speeds also vary considerably. Fast tape drives can transfer as much as 20MB (megabytes) per second.

Display Adaptors: The plug-in card in a desktop computer that creates the electronic signals required by the monitor. Also called a "video card" or "graphics card," modern display adapters use the PCI Express interface, while earlier cards used PCI and AGP. The display adapter determines the maximum resolution, refresh rate and number of colors that can be displayed, which the monitor must also be able to support. On many PC motherboards, the display circuits are built into the chipset, and a separate plug-in card is not required.