Chapter -2 Computer Hardware

The Significance of Hardware Most business people rightly suspect that knowing how to use computer technology is more important to their personal productivity & their firm’s competitive advantage than knowing the technical details of how the technology functions . But some basic understanding of Computer Hardware Design & Function is essential because organizations frequently must assess their competitive advantage in terms of computing capability.

Computer Based Information Systems (CBISs) are composed of Important decisions about computing capability have to be made , & to the large degree these decisions turn on an understanding of hardware design. Computer Based Information Systems (CBISs) are composed of Hardware Software Database Telecommunications Procedures People

It Consists of the following Hardware refers to the physical equipment used for the Input, processing, Output & Storage activities of a Computer System. It Consists of the following Central Processing unit (CPU) Memory ( Primary & Secondary storage) Input Technologies Output Technologies Communication Technologies

CPU (Central Processing Unit) CPU Pronounced as “ Sea-Pea-You”, is your Computer’s brain. If it’s real smart, it’s called a Pentium & it has MMX, I,II,III,IV tacked to the end of it. MMX ,I,II --- doesn’t stand for anything , but it gives the chip-increased capabilities for playing Multimedia & faster processing speed. Older chips are known by their numbers: 486, 386 & so on

Basic Computer Organization The basic five Operation of a computer Systems Inputting Storing Processing Outputting Controlling

CPU (Central Processing Unit) Basic Organization of Computer Systems Storage unit Secondary Storage Program & Data Output Unit Input Unit Information (Results) Primary Storage CU Indicates flow of instructions & data Indicates the control exercised by the control unit ALU CPU (Central Processing Unit)

Input Unit Data & Instructions must enter a computer system before the computer can perform any computation on the supplied data. Eg- Data can be entered using a keyboard in a manner similar to typing & this differs from the way in which data is entered through a scanner , although another type of input device. However, a computer’s memory is designed to accept input in binary code & hence , all input devices must transform input signals to binary codes .

In short, an input unit performs following functions It accepts Instructions & data from outside world. It converts these instructions & data in computer acceptable form It supplies the converted instructions & data to computer systems for further processing.

Output Unit An output units performs the reverse operation of that of an input unit. As computers work with binary code, results produced are also in binary form. Therefore , before supplying the results to outside world , the system must convert them to human readable form. Units called output interfaces accomplish this task.

In short , an output unit performs following functions. It accepts the results produced by a computer, which are coded form & hence , we cannot easily understand them. It converts these coded results to human readable form. It supplies the converted results to outside world.

Storage Unit Data & instructions entered into a computer system through input units have to be stored inside the computer before actual processing units. Similarly , results produced by a computer after processing have to be kept somewhere inside the computer system before being passed on to a output unit. It provides space for storing data & instructions, intermediate results, & results for output.

In short , a storage unit holds Data & Instructions required for processing. Intermediate results for processing Results for output , before they are released to an output device.

Storage unit of all computers is comprised of following two types of storage. Primary Storage Secondary Storage

Primary Storage Primary Storage of a computer , also called as its main memory, is used to hold the program instructions & data, intermediate result of processing , & recently produced results on which the computer is currently working. These piece of information are represented electronically in the main memory chip’s & while it remains in the main memory , cpu can access it directly at a very fast speed. However , primary storage can hold information only while computer system is on.

As soon as the computer system switches off or resets, the information held in primary memory is erased. Moreover , primary storage normally has limited storage capacity because it is very expensive.

2. Secondary Storage. Secondary storage of a computer also know as auxiliary storage, is used to take care of the limitation of Primary Storage. That is , it supplements the limited storage capacity & the volatile characteristic of primary storage. This is because secondary storage is much cheaper than primary storage & it can retain the information even when a computer system switches off. Magnetic disk is the most commonly used secondary storage medium.

Arithmetic & Logic Unit ALU of a computer system is the place where actual execution of instructions take place during processing operation. To be more precise , calculations are performed & all the comparisons are made in ALU. Data & instructions stored in primary storage before processing are transferred as & when needed to ALU where processing takes place. Intermediate results generated in the ALU are temporarily transferred back to primary storage until needed later.

Hence, data may move from primary storage to ALU & back again to storage many time before processing is over. ALU are designed to perform the four basic Arithmetic operation & logic operations.

Control Unit It manages & coordinates the entire computer system. It obtains instructions from the program stored in main memory, interprets the instructions & issues signals causing other units of the system to execute them. Although it does not perform any actual processing on data, the control unit acts as a nervous system.

+ CPU ( Central Processing Unit) CPU CU ALU = It is the brain of the computer system. It is responsible for controlling the operations of all the other units of a computer system.

Input device from cd of sinha

Computer Hierarchy Micro Increase Computers In Technology Mini Computes Main Frame Computers Super Computers

Strategic Hardware Issues The Majority of this chapter has explained how hardware is designed & how it works. But it is what the hardware enables, how it is advancing , & how rapidly it is advancing that are the more complex & important issues for most businesspeople. In many industries, exploiting computer hardware is a key to competitive advantage.

Successful hardware is useful in following ways. Productivity:- Hardware Technology can affect both personal & organizational productivity. Changing Work Style :-Advances in Technology is useful in changing the style of the work. New Product & Service:- New Technology is helpful in giving the new services & products. Improved Communications:-Multimedia is often thought of as the basis of an entertainment.

Output Devices Commonly use output device Monitors Printers Plotters Screen Image projector Sound cards & Speakers

Monitors The on-screen display enables the user to view the results of data processing Two types of Monitors 1) Cathode Ray Tube 2) Flat panel Monitor

2) Printers Two types of Printers Non-Impact Printer Impact printer

Impact Printers These printers can produce a page, a line, or a character at a time. It can Produce Multiple Copies at a time 1) Dot matrix Printers 2) Drum Printers

Non-impact Printers These are the most widely used printers for personal computer todays. 1) Inkjet Printers 2) Laser Printers.

3) Plotters Plotters are used for printing quality graphics & drawings Three types of plotters Flatbed Plotters Drum Plotters Inkjet Plotter

4) Screen Image Projector An output device that can be plugged directly to computer for projecting information from a computer on to a large screen. Full fledged multimedia presentation with audio, video , image, & animation can be prepared.

5) Sound Cards & Speakers Sound Card & speakers enable the users to receive an audio output . Such sounds include the output of recorded sound files & even speech