The The Computer Computer SystemsSystems

Computer System

CPUIs the brain of the PC.All program instructions are run through the CPU

Control UnitThis decodes and executes the program.

ALUThis performs all mathematical and comparision instructions.

Main MemoryStores the program that is being decoded by the CPU.RAM = volatile ROM = permanent

Backing StoreHard Disk, USB Disk, etc. Stores programs permanently.

InputKeyboard, Data Reader, etc.

OutputScreen, Printer, etc.

Buses

Control Bus Carries control Signals to read or to writeData Bus Carries Data between Processor & Memory

Address Bus Carries the address (location) of data or program instruction. Carries the address of input or output port.

Motherboard

Motherboard

ProcessorThe primary chip of the system that oversees all the other components of the system

Types of Processor

1st Generation 80863rd Generation 80386 called 386 32bit computing6th Generation Pentium II 64 bit computing

Celeron IIDuron 128 bit computing

8th Generation Intel Core 256 bit computing

ComponentsBIOSBasic Input/Output System. support data transfers between the various components.

RAMStores the programs, and data temporarily while the CPU runs the program.When the computer is turned off the contents are lost.

ROMStores programs/data but does not allow updates. Its contents nonvolatile –are not lost when the computer is switched off.

HARD DISKA magnetic disk can store upto 100 gigabytes.

IDE - Integrated Drive Electronics Disk devices connect to the PC through an (IDE) interface.

IDE uses a special configuration called master and slave.

PortsA port is a connection or plug in on the PC.

USB -Universal Serial Bus An standard that supports data transfer rates of 12 Mbps

Serial Transfer of data one bit at a time.Parrallel Transfer of data several bits at a time. (faster than serial)

Firewire A very fast external bus that supports data transfer rates of up to 400 Mbps

Typical PC System