S3 Computer Literacy

Computer Hardware

Overview of Computer Hardware

MotherboardCPURAMHarddiskCD-ROMFloppy DiskDisplay CardSound CardLAN Card

MotherboardIt is the main circuit board that links all the hardware components together.There are many chips or IC (Integrated Circuit) on the motherboard which contains millions of transistors.

Bus LinesBus line is a physical wiring that connects the components of the computer system on the motherboard.

Types of BusSystem Bus

Data transmission between CPU and the main memory via System Bus. It is also known as the Front Side Bus (FSB).

Peripheral BusData transmission between main memory and peripherals via Peripheral Bus.

Bus WidthIt is the size of the bus lines.It determines the number of bits that the computer can transmit at one time (say, one clock cycle).

eg: a 32-bit bus can transmit 32 bits at a time.the larger the bus width, the faster the transmission.

Examples of Peripheral Bus

ISA BusOld sound cardFaded out already

PCI BusFor most of the interface card like

LAN CardMODEMSound CardCapture Card

Examples of Peripheral Bus

AGP BusDesigned for Display Card only

USB BusFor most of the peripheral

MP3 Player, Digital CameraKeyboard, MousePrinter, Scanneretc

CPU (Central Processing Unit)

It interprets and performs instructions of a computer program.The most determining factor in how powerful a computer is.A CPU in a common PC system is known as the microprocessor.

A model of Computer

CPUA CPU consists of two parts, the ALU and the CU.Both the ALU and the CU contains registers, which are

high-speed memory temporarily hold data and instructions during processing.

CPU Performance depends on…

Clock ratethe speed at which the CPU can execute an instruction.unit is Hertz (Hz).

CPU Performance depends on…

Cache Memorymemory that is placed inside the CPU. it is random access memory (RAM) that a microprocessor can access more quickly than it can access main memory.acts as an intermediate between registers and the main memory.it stores some frequently accessed data so it shorten the time of accessing the RAM.increasing the size of the cache memory will greatly improve the overall performance of the computer system.

Different kind of CPUIntel

CeleronPentium 4Xeon

AMDDuronAthlon XPSempronAthlon 64

Common features

Clock rate > 2GHz

DifferencesWord SizeCache Memory SizeFront Side BusNo. of transistors

Main MemoryStorage media installed on the motherboard

store data and instruction to be executed by the CPU

Main memory is classified intoRAMROMCMOS

RAMRAM – Random Access MemoryRAM is volatile

data is lost when the power to the computer is turned off

The instructions and data for the job performing are written to RAM and read from it as needed.

RAMTwo operations of RAM

Loading means copying data from the secondary storage to the main memory Saving means copying data from RAM to the non-volatile secondary storage.

Types of RAMSRAMDRAMSDRAMDDR-RAM

ROMROM – Read Only MemoryROM is non-volatile

Data are stored permanentlyData can only be read but cannot be changed

Store instructions and tells the computer how to load the operations system when booting up

Basic Input/Output System (BIOS)

CMOSCMOS - Complementary Metal-Oxide Semiconductor MemoryIt has the characteristics of both ROM and RAM, ie:

it is non-volatileinformation in CMOS can be changed

In computer, CMOS stores the configuration information about a computer like capacity of the hard disk and the current time and date.

Ports and Interface CardsThe interface between peripheral devices and the CPU.A port is built on the motherboard while an interface card is inserted into slots on the motherboard.Sometimes, an interface card may become a built-in function on the motherboard.

Case StudiesFor the following 2 computers, state its specifications.You should try to point out what are those hardware components and how they are different.

Case Studies 1The followings are the true pictures

Case Studies 2The followings are the true pictures