computer-2-Computer-System-1-1.pptxbvghghbbv
- 2. 2 Computer System Computer systems include the computer along with any software and peripheral devices that are necessary to make the computer function.
- 3. Parts of The Computer System •A complete computer system consists of mainly four parts. 1. Hardware (The computer) 2. Software (Programs) 3. Data (Information) 4. User (People) Hardware: Hardware means the physical structure of a computer, the parts that can be touched by us. All the components attached to the computer like Keyboard, Mouse, Monitor, Printers are hardware.
- 4. Software: Software is a set of instructions that makes the computer perform tasks. In other words we can say that, software tells the computer what to do. Here the program refers to any piece of software. Data: Data consist of individual facts or pieces of information that by themselves may not make much sense to a person. A computer primary job is to process these tiny pieces of data in various ways, converting them into useful information. Users: Peoples are the computer operators, also known as users. One can argue that some computer systems are complete without a person’s involvement; however no computer is totally autonomous.
- 5. 1. Computer Hardware – A generic name for the various devices that make up a computer system 2. Computer Software – Set of instructions that direct the computer hardware to perform a particular task
- 6. 6 Hardware • Any visible part of a computer which can be seen and touched is known as hardware. • Hardware components are involved in the data processing cycle as an input, output or as both. • On data processing cycle, there are hardware devices used to enter data which are known as input devices and other hardware devices used to display the information are known as output devices but there are also devices used as both input and output devices. • Moreover others are involved in the processing cycle such as CPU, RAM, ROM.
- 7. 7 Hardware Components 1. Input Unit – feeds data & instruction to the computer system 2. Output Unit – displays / prints the results of the processing 3. CPU – is the brain of the computer that caries out the processing of the data as per the instructions 4. Memory – stores data and programs within and/or outside the computer system 5. Power supply – used to convert AC into DC and provide appropriate power for each of internal components of a PC.
- 8. 8 Input Devices • Input is all information put into a computer. • Input can be supplied from a variety of sources: – A person – A storage device on computer – Another computer – A peripheral device – Another piece of equipment, such as a musical instrument or thermometer
- 9. 9 Input Devices… • Input devices gather and translate data into a form the computer understands. • Primary input devices: – Keyboard - Most common input device; used to type in commands and data. – Mouse or trackball: enhances user’s ability to input commands, manipulate text, images.
- 10. 10 Input Devices… • Scanners: are peripheral input devices which allow users to import: – Text – Graphics – Images • Specialized software aids in translating information into a format the computer can understand and manipulate.
- 11. 11 Input Devices… • Digital Cameras: are peripheral input devices that allow users to create pictures and/or movies in a digital format. –Some require specialized software to import images into the computer. –Some record digital images directly to a disk that can be read by the computer.
- 12. Some input devices • Mouse • Keyboard • Scanner • Touch pad • Light pen • Joysticks • Microphones • Digital Cameras • Touch Screen • Bar Code Reader • Trackball • CD-ROM 44
- 13. Output Devices Used to display processed information to the user either in softcopy or hardcopy Soft copy – output displayed on a computer screen. It is the primary output medium. E.g. Monitor, speaker, LCD projector Hard copy – output produced on paper or micro film. E.g. Printers, plotters. 13
- 14. 14 Output Devices… • Monitors: are the most commonly used output device. • Most monitors use a bitmap display. – Allows user to resize the display. – Divides the screen into a matrix of tiny square “dots” called pixels. – The more “dots” a screen can display, the higher the resolution of the monitor.
- 15. 15 Output Devices… • Monitors are connected to a computer system via a port integrated on the video adapter or graphics card. • Graphics cards convert digital data output from software to analog data for display on monitors.
- 16. Output Devices… Printer • Most widely used output devices to prepare printed paper documents • There are Impact and Non-impact printers • Impact printers Form characters by striking an inked ribbon with hammers against paper E.g. Dot matrix printers & ink printers 16
- 17. Output Devices… • Non-impact printers: Form characters without physical contact between a printer and paper E.g. Laser jet printers Plotters capable of drawing complex shapes with multiple colors 17
- 18. Output Devices… • Monitors • Printer • LED/LCD Panels • Speakers • Headphone • Plotters • Projectors 18
- 19. CPU The brain of a computer system where calculations and decisions are made.
- 20. Central Processing Unit • CPU or microprocessor is often described as the brain of a computer. • CPU is an integrated circuit or “chip” which processes instructions and data. It is the place where data processing takes place • The system's memory also plays a crucial role in processing data. • Both the CPU and memory are attached to the system's motherboard, which connects all the computer's devices together, enabling them to communicate. 20
- 21. Components of CPU 1. Processor: The procedure that transforms raw data into useful information is called processing. The processor is like the brain of computer system. A personal computer’s processor is usually a Single or a set of chips contained on a circuit board 2. Memory devices: Memory devices are of two types: *RAM is like an electronic scratch pad inside the computer. RAM is a volatile memory. *ROM is a non-volatile memory. ROM permanently stores its data, even when the computer is shut off.
- 22. 3. C U (control unit): All the computer’s resources are managed from the control unit. It act as a traffic signal directing the flow of data through the CPU as well as to and from other devices. 4. A L U (Arithmetic logic unit): The work of the ALU is to perform arithmetic and logical operations. Arithmetic operation include addition, subtraction, multiplication, and division. Logical operation include comparison, such as determining whether one number is equal to, greater than, or less than another number.
- 23. The Control Unit Controls the entire operation of the computer. Directs the flow of data through the CPU, and to and from other devices. The control unit stores the CPU's microcode, which contains the instructions for all the tasks the CPU can perform. 23
- 24. The Arithmetic Logic Unit The actual manipulation of data takes place in the ALU. Performs the arithmetic operations and the logical comparisons Controls the speed of calculations; Larger & powerful computers speed are measured in: Pico seconds Nano seconds, etc. 24
- 25. 25 Computer Memory • Computer memory refers to devices that are used to store data or programs (sequence of instructions) on temporary or permanent basis. • You can store data on your hard disk, that used to store data permanently, while data which is being processed is stored in RAM (Random Access Memory)
- 26. 26 How computer memory is measured? • Bit:1 or 0 level of storage • Byte: A byte consists of eight bits. • Kilobyte: A kilobyte (KB) consists of 1024 bytes. • Megabyte: A megabyte (MB) consists of 1024 kilobytes, approximately 1,000,000 bytes. • Gigabyte: A gigabyte (GB) consists of 1024 megabytes, approximately 1,000,000,000 bytes. • Terabyte: A terabyte (TB) consists of approximately 1,000,000,000,000 bytes.
- 27. 27 Types of Computer Memory Computer memory or storage devices are classified into two broad categories: i. Primary memory / storage Internal storage RAM and ROM ii. Secondary memory / storage External storage CD / DVD, Hard disk, floppy disk, magnetic tape
- 28. 28 Primary Memory Two types of primary memory: • Main memory (RAM): The main working area of the computer The CPU can utilize only those instructions and data that are stored in main memory • ROM: Stores small programs permanently
- 29. 29 RAM • Stands for Random Access Memory • “Waiting room” for computer’s CPU. • Working place of computer used to store data temporarily. • Holds instructions for processing data, processed data, and raw data. • The amount of RAM in a PC has a direct impact on the system's speed.
- 30. 30 RAM… • The more RAM a PC has, the more program instructions and data can be held in memory, which is faster than storage on disk. • Ram is measured by: –Capacity (in Megabytes or Gigabytes) –Speed (in Nanoseconds)
- 31. 31 RAM… • All software applications will have RAM specifications listed on their packaging. • Many applications list both a minimum and a recommended amount of RAM necessary to run the software. • Be cautious about buying software for a system based on minimum requirement.
- 32. 32 ROM • Read Only Memory (ROM) as the name suggests is a special type of memory chip which holds software which can be read but not written to. • A good example is the ROM-BIOS chip, which contains read-only software. • Often network cards and video cards also contain ROM chips.
- 34. 34 Secondary Storage Devices Storage devices designed to retain data and instruction in a more permanent form. Non-volatile storage media. Capacity and speed are important considerations when selecting a new storage device for a PC. Currently used ones: • hard disks, • floppy disk, • optical disk (CD) • Versatile disk (DVD) • Flash disk