Lec 2 introduction to computer -ii
- 1. Introduction to Computer -II AHSAN ASHFAQ AHSAN ASHFAQ | OMT I | INSTITUTE OF MANAGEMENT SCIENCES PESHAWAR 1
- 3. 1. Speed The ability to perform the information processing cycle with amazing speed. ◦ Today's processors are multi-core GHz processors capable of processing over 100 billion instructions per second.
- 4. 2. Accuracy All computer systems besides having amazing speeds have nearly 100% accuracy.
- 5. 3. Reliability Reliability (low failure rate). Computers need to be reliable for people to use them and have confidence in them. If they are not reliable, then they will quickly be abandoned. it represents the ability of the computer to work for a particular amount of time with out breaking down.
- 6. 4. Memory Ability to store huge amounts of data and information. ◦ Internal memory (Main memory) ◦ External memory (secondary storage) Main memory: ◦ It holds data that will be used shortly. Secondary storage: ◦ It holds data that will be used later.
- 7. 5. Diligence Computer can work for hours without any break and creating error.
- 8. 6. Versatility We can use computer to perform completely different type of work at the same time.
- 9. 7. Logical Computer can easily solve complex mathematical problems.
- 10. 8. Automation Internally the overall process of the computer is automated and all the devices are communicating with each other.
- 11. Block Diagram of the Computer
- 12. 1. Input Unit Computer need to receive data and instruction in order to solve any problem. The input unit consists of one or more input devices, to input the data and instructions into the computer. ◦ For Examples: mouse, keyboard, microphone. Input devices: ◦ Accept the data and instruction from user ◦ Convert it to a form that the computer can understand.
- 13. 2. Output unit The output unit is responsible to convert and provides the information or results of a computation to users. For example: Printers, Monitors, multimedia
- 14. 3. CPU: Central Processing Unit The CPU is like brain of computer that performs the following functions: ◦ It Performs all calculations ◦ It takes all decisions ◦ It controls all units of the computer ◦ It has the following important units: ◦ Control Unit ◦ Arithmetic logic unit ◦ Registers ◦ Bus
- 15. 4. Control Unit It is responsible for directing and coordinating the computer system activities. It does not execute instructions by itself. It tells other parts of the computer system what to do. It determines the movement of electronic signals between the main memory and arithmetic logic unit.
- 16. 5. ALU: Arithmetic logic unit It performs all the arithmetic and logical functions i.e., addition, subtraction, multiplication, division and comparisons. Comparisons: ◦ Greater than ◦ Less than ◦ Equals ◦ Not equals
- 17. Registers It is a special temporary storage location within the CPU. It is very quickly: accept, store and transfer data or instructions that are being used immediately.
- 18. Data Bus It is an electrical pathway through which data are transmitted between the various computer components.