Computer System
Chapter 1: Computer System
Introduction
Computer system is a functional hardware and software setup where everything needed to implement.
The basic working principles are to receive user input, process data and also the capability to create information for storage and output. Computer system is also involves looking back at the timeline of computer evolution over the decades.
Objectives
- After completion of this chapter, students will able to-
- -Understand the purpose and elements of computer system.
- -Recognize the types of computers and their evolution.
- -Understand and define computer architecture.
- -Describe input, output and storage devices.
1.1 Introduction of Computer
1.1.1 Definition
Computer is an electronic device which takes raw data as input from user and processes these data with the set of instructions (called program), gives the result (output) and saves for the future use. Computer can process both numerical as well non-numerical (arithmetic and logical) calculations.
Figure 1: Set of Computer
The term 'computer' is derived from the Latin term 'computare', this means to calculate. Computer is designed to work with information which represents the decimal numbers through a string of binary digits.
An important class of computer operations in some computing platforms is the accepting of input and the output of results formatted for human consumption. The interface between computer and human operator is known as the user interface.
Complex computers also include the means for storing data (including the program, which is also a form of data) for necessary duration. A program may be invariable and built into the computer or different programs may be provided to the computer.
Advantages and Disadvantages of Computer
Computer are mostly used machine in our daily life in various forms like laptops, desktops, mobile phone, television, tablets etc. Even computer terms are essential part of our life. It has both advantages as well as disadvantages as following:
The major advantages of computer are as follows:
- Any work can be done easily, faster as well as accurately.
- Communication can be done easily as required.
- Many resources can be shared with many computers.
- Data can be stored safely for the future purpose.
- It provides more accurate answer and calculation.
The major disadvantages of computer are as follows:
- Maintenance and repair are required frequently.
- It can create unemployment because it works faster than many people.
- We need to invest huge money to buy and update computers.
- Highly qualified professionals are needed to operate and handle computer smoothly otherwise misunderstanding can arise.
- There are security threads of virus, malware, data privacy as well as piracy.
Characteristics of Computer
There are some important characteristics (features) of a computer which are described below:
High Speed: Computer can work very fast which takes few seconds for calculations where as human take hours to complete the same task. We can determine the speed of computer in terms of microsecond (10-6 part of a second) or nanosecond (10 to the power -9) part of a second. The computer present in the modern world has the speed of nano, pico and femto second.
Automatic: Computers are automatic device which can execute the process without any intervention of user once they are assigned to a work. Once the data or instruction are fetched from the secondary devices such as optical disks, hard disks etc. Immediately they get stored into RAM (primary memory) and then sequentially they get executed.
Versatile: It means the capacity to perform various kind of task. They can be used as personal computers, for home uses, for business, weather forecasting, space explorations, teaching, ticket reservation, banking and medicine. All Modern computers can perform different kind of tasks simultaneously.
Diligence: A computer never gets tiredness, lack of concentration, weakness, etc. It can work for hours without creating any error. If millions of calculations are to be performed, a computer will perform every calculation with the same accuracy.
Accuracy: They are reliable and strong. It ever makes a mistake. The accuracy of computer is very high and every calculation is performed with the same accuracy. The accuracy level is determined on the basis of design of computer. The errors in computer are due to human and inaccurate data. Most probably the error occurs due to the user rather than the computer. Only accurate robots are used to perform the operations for the patients since human hands are not flexible for making operations.
Memory: Secondary storage devices are the key for the data storage. They store the data for which the user wants to retrieve in the future. There are various secondary devices are Floppy disk. Optical disks, Zip drives, etc. The data of smaller size can be easily fetched and they can be copied to the primary memory (RAM).
Reduction of cost: Computers are one-time investment in order to achieve a long term gain. Though the investment is high they reduce the cost of each and every transaction. They reduce man power and leads to an elegant and efficient way for computing various tasks.
Power of Remembering: Computer has the power of storing any amount of information or data. Any information can be stored and recalled as long as you require it, for any numbers of years. It depends entirely upon you how much data you want to store in a computer and when to lose or retrieve these data.
Application Areas of Computers
Computers are used in various areas including education and training, information provision, leisure and entertainment, virtual reality and combination of these areas. It uses different types of media such as text, audio, image and video to entertain or to provide a message. Some of the important application areas of computer are listed below.
Education Entertainment Industry Medical Field
Figure 1.1: Application areas of computer
Home: Computers are commonly used at home for various purpose watching movie, playing games, utilities payments, email, internet etc. like.
Industry: Industry uses computer for various purpose like keeping inventory, Payroll, financial calculation, Video conferencing, interior design, digital marketing and online trading etc.
Bank: Computers are used to keep financial records of customer; ATM machine are used to withdraw as well as deposit money. Customer can withdraw and deposit money from any branch of any cities by using computer.
Entertainment: Computers are used to listening music, watching movies online; it can use to edit and rearrange music as well as video. We can play any artificial instrument online with the help of computer.
Education: Computers are widely used electronic machine in the field of education. Students can research every information over internet by using computer. They can take online classes, audio-visual classes as well as took online exam to their convenient time.
Communication: Transferring a message, an idea, a picture or speech from one place (sender) to another (receiver) is called communication. With the help chatting, e-mail, FTP, video-conferencing, messenger one can communicate with each other frequently.
Health Care: Now a day's most of the medical information, reports, prescription is digitized. In medical sector, computer can be used in various ways and treatments like ECG's, CT-Scan, MRI etc. Now a day's major operation can also be done by laser therapy.
Military: Computers are most essential tools for developing missiles and other equipment in the defense. It is not possible to designing, maintenance construction of weapons and controlling their function without computers. The list of the criminals and the records are maintained regularly in the system.
Transportation: Computers have made possible for planes to land in foggy and stormy atmosphere. Computer connects to the various sensor attached to the planes, aircraft which controls the plane's altitude, position, speed, height and direction. Now a day's auto-pilot feature has developed which is connected to the computer to guide the planes by capturing all the information.
Tourism: Hotels use computers to speed up billing and checkout the availability of rooms. Most of the fast food café are using computers, tablets in substitute of KOT as well as menu. Airline reservations for booking tickets.
Some Terminologies Used in Computer
Hardware: Computer hardware consists of the components that can be physically touched. The functions of these components are typically divided into three main categories: input, output, and storage. All the physical components are computer hardware.
Software: Software is the set of instructions a computer uses to manipulate data, such as a word-processing program. These programs are usually stored and transferred via the computer's hardware to and from the CPU. Software also governs how the hardware is utilized; for example, how information is retrieved from a storage device. The interaction between the input and output hardware is controlled by software called the Basic Input Output System (BIOS).
Program: It is a set of instructions which directs a computer to perform some processing function or combination of functions. A program can be executed many different times, with each execution yielding a potentially different result depending upon the options and data that the user gives the computer.
Command: Commands are instruction given to a computer to function, operation, or program. Commands are an integral part of the interface between the user and computer. Commands for similar functions differ depending on the computer system and operating system being used.
Information: Information are the collection of data displayed in a very systematic way, so that it is meaningful when presented. Information are always meaningful.
Firmware: The software routines stored in read-only memory (ROM). I is permanently stored by the manufacture company.
Random Access Memory: RAM is a semiconductor-based memory that can be read and written by the microprocessor or other hardware devices The storage locations can be accessed in any order. It is a volatile (temporary) memory.
Read Only Memory: ROM is a non-volatile (permanent) memory that contains instructions or data that can be read but not modified.
Memory: It is a place where we can store data and programs f temporary or permanent use. There are different types of memory li primary and secondary memory.
