20 the components of the system unit
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The system unit contains the main electronic components of a computer, including the processor, motherboard, memory, and storage devices. The processor performs instructions and calculations using components like the control unit, arithmetic logic unit, and registers. The motherboard connects the components and includes expansion slots for additional hardware. Peripheral devices like keyboards, mice, and monitors connect to the system unit but are not contained within the case.
20 the components of the system unit
- 1. The components of the system unit Lecture 20 Zikria Mian
- 2. • System unit is the case that contains electronic components of a computer used to process data. – Is available in a variety of shapes and sizes – The case of sytem unit is also known as chassis or casing • Keyboard, mouse, microphone, monitor etc are peripheral devices
- 4. The Components • Processor – Control unit – to manage instructions and initiate appropriate tasks – Arithmetic Logic Unit (ALU) – to perform arithmetic and logical operations – Registers – high speed storage locations to temporarily hold instructions / data – System clock (that sets the operating pace)
- 5. • Motherboard MEMORYInput Devices Output Devices Storage Devices Processor
- 6. The Machine Cycle • For every instruction, the processor follows a four step cycle called the Machine Cycle – Fetching – Decoding – Executing – Storing • Some processors can execute one machine cycle at a time • Most modern computers support Pipelining
- 7. Processors comparison • Intel – Pentium, dual core……. • AMD – Athlonx2 • IBM • Motorolla Heat control through Heat Sinks, Heat pipes and Liquid Cooling
- 9. Data Representation • Computer can only understand two discrete states, that is, On and Off represented normally as 1 and 0 • Computers use binary system and a bit is the smallest unit of data. – 8 bits combine to make a byte and can represent 256 individual characters – Several coding schemes are followed to represent characters • ASCII • EBCDIC • Unicode (16-bit)
- 10. Memory • 1 KB = 1,024 bytes • 1 MB = 1,048,576 bytes • 1 GB = 1,073,741,824 bytes • Two types of memories – Volatile – Non-volatile
- 11. Types of Memory • RAM – Dynamic RAM – SDRAM (DDR2, DDR3) – Rambus DRAM (pipelining technology) – Static RAM – Magnetoresistive RAM
- 12. Types of Memory (contd.) • Cache – Memory Cache (L1, L2, L3) – Disk Cache • ROM • Flash Memory (Complimentary Metal- Oxide Semiconductors- CMOS) • Hard Disk
- 13. Expansion slots and Adapter Cards • Sound Card • Video Card • Modem • Network card • Plug and Play devices • RAM
- 14. Ports and Connectors • A port is a point at which a peripheral attaches to the system unit. A connector joins a cable to the respective port. • Serial ports – That transfer one bit at a time • Parallel ports – That transfer more than one bit at a time • USB ports – Can connect upto 127 different peripherals with a single connector • Special purpose ports • IrDA port / Bluetooth port
- 15. • BUS – Data transfers internally within the circuitry along electircal wires. Each wire is called a bus. – Data Bus – Address Bus Each bus has a particular width and clock speed.
- 16. BAYS and Power Supply • The system unit usually has slots to install additional drives like extra hard disk, DVD drive etc • The power supply connects to the motherboard, monitor, disk drives. Usually comes with extra wires to allow installation of additional hardware.