1. BMTS 242: Computer and Systems Lecture 1: Introduction to Computer System Yousef Alharbi Email y.alharbi@sau.edu.say.alharbi@sau.edu.sa Website http://faculty.sau.edu.sa/y.alharbi/enhttp://faculty.sau.edu.sa/y.alharbi/en

2. Course objectives To understand the computer system. Develop the ability to learn the main physical parts of the computer. How to deal with computer software. Practical part of this course should be enough to develop the students technical skills including software and hardware. BMTS 242: Computer and Systems

3. Assessment BMTS 242: Computer and Systems 1 st Midterm Middle of term 20% 2 nd Midterm Week 11 or 12 20% Practical Exam Week 15 or 16 20% Final Exam Week 15 or 16 40%

4. Introduction There are some definitions should be understood before beginning with this course; Computer Program Hardware Software BMTS 242: Computer and Systems

5. Introduction A computer is an electronic device, operating under the control of instructions (software) stored in its own memory unit, that can accept data (input), manipulate data (process), and produce information (output) from the processing. Generally, the term is used to describe a collection of devices that function together is a ‘’ system’’. BMTS 242: Computer and Systems

6. Introduction A program is a series of steps to accomplish a given task. In general usage, a program might refer to everyday instructions, such as instructions to change a tire or register for a college class. In computer, however, the term “program” refers to a series of steps given to a computer. BMTS 242: Computer and Systems

7. Introduction Hardware refers to all the physical devices that make up a computer system, both those inside the computer “case” (e.g. hard disk) and those outside the case, like monitor, keyboard, and mouse. BMTS 242: Computer and Systems

8. Introduction BMTS 242: Computer and Systems Software refers to the programs the computer executes. For example, the word processor Microsoft Word, or the computer game “Half-Life,” is software. By analogy, when you play a movie in a DVD player, the movie is the software and the player is the hardware.

9. Classification of Computers Computers can be classified based on their power and use into the following type; BMTS 242: Computer and Systems Personal computer Workstation Mainframe Minicomputer Supercomputer Server Client

10. Classification of Computers BMTS 242: Computer and Systems A personal computer is designed for use by one person at a time. The computers people use at home or students use in school laboratories are personal computers.

11. Classification of Computers BMTS 242: Computer and Systems A laptop is a compact personal computer with all the devices shrunk into one container to make the computer easily portable.

12. Classification of Computers BMTS 242: Computer and Systems A workstation is also a computer designed for use by one person at a time, but it is connected to a network—a set of computers connected together to share data. At an insurance company, for example, all the employees may have computers on their desks with the computers connected to a network so they can share customer data. While computers intended as workstations may be more powerful than personal computers, this is not always the case.

13. Classification of Computers BMTS 242: Computer and Systems Workstation computer

14. Classification of Computers BMTS 242: Computer and Systems A mainframe is a powerful computer that is shared by multiple users at one time. Each user has a terminal, which in this context is simply a keyboard and screen combination used to access the mainframe. This type of computers is used by companies and governmental organization for critical applications such as; industry and consumer statistics, transaction processing and bulk data processing (census).

15. Classification of Computers BMTS 242: Computer and Systems Mainframe computer

16. Classification of Computers BMTS 242: Computer and Systems A minicomputer is any computer powerful enough to be used by multiple people but not powerful enough to be considered a mainframe. A supercomputer is among the fastest of current computers. Because this classification is based on performance, no computer can stay in this category forever. Systems that were considered supercomputers ten years ago are ordinary in their abilities today.

17. Classification of Computers BMTS 242: Computer and Systems A server is a computer on a network that provides a service to other computers. Mainframes are often used as servers, but not every server is a mainframe. Even a personal computer is powerful enough to be a server.

18. Classification of Computers BMTS 242: Computer and Systems A client is a computer that uses a server for some service. An example of the client-server relationship is an automated teller machine. The ATM is a computer, but all it really knows is how much money it has left inside of it. When you request money from your account at an ATM, the ATM must consult a central computer at your bank to determine if your account has a high enough balance to grant your request and to debit your account once you have been given your money. The ATM is the client in this relationship, and the central computer at the bank is the server.

19. What Does A Computer Do? BMTS 242: Computer and Systems Computer performs five major functions: 1. Input: This is the process of entering data and programs into the computer system. 2. Storage: The process of saving data and instructions permanently is known as storage. Data has to be fed into the system before the actual processing starts. It is because the processing speed of Central Processing Unit (CPU) is so fast that the data has to be provided to CPU with the same speed. The storage unit performs the following major functions: - All data and instructions are stored here before and after processing. - Intermediate results of processing are also stored here.

20. What Does A Computer Do? BMTS 242: Computer and Systems Computer performs five major functions: 3. Processing: The task of performing operations like arithmetic and logical operations is called processing. The Central Processing Unit (CPU) takes data and instructions from the storage unit and makes all sorts of calculations based on the instructions given and the type of data provided. It is then sent back to the storage unit. 4. Output: This is the stage of producing results from the data for getting useful information after processing. 5. Control: Controlling of all operations like input, processing and output are performed by control unit. It takes care of step by step processing of all operations inside the computer.

21. Computer System BMTS 242: Computer and Systems In order to carry out the five operations mentioned above, the computer allocates the task between its various functional units. The computer system is divided into several units for its operation.

22. Computer System BMTS 242: Computer and Systems Central Processing Unit (CPU): The place where decisions are made, computations are performed, and input/output requests are authorised. Memory: stores information being processed by the CPU Input devices: allows people to supply information to computers Output devices: allows people to receive information from computers Buses: a bus is a subsystem that transfers data or power between computer components inside a computer.

23. Thank You for Listening BMTS 242: Computer and Systems