Introduction To Computer

Hardware

Computer Overview

Processor

RAM

ROM

Motherboard

Hard Disk

Cards

Ports

BIOS

Peripherals

Cabinet

An electronic device that stores, retrieves and

processes data, and can be programmed with

instructions.

What is a Computer?

A computer is composed of hardware and software, and can

exist in a variety of sizes and configurations.

Hardware & Software

The term hardware refers to the Physical

components of your computer such as the system

unit, mouse, keyboard, monitor etc.

The software is the instructions that makes the

computer work. Software is held either on your

computers hard disk, CD-ROM,DVD or on a diskette

(floppy disk) and is loaded (i.e. copied) from the disk

into the computers RAM (Random Access

Memory),as and when required.

Types of Computers

Mini and Mainframe Computers

Very powerful, used by large

organizations such an banks to control the

entire business operation. Very expensive!

Personal Computers

Cheap and easy to use. Often used as stand-

alone computers or in a network.

Processor

Processor is the brain of your computer

Some key concepts

Clock : In a computer, clock speed refers to the

number of pulses per second that sets the tempo for

the processor.

Cache :A small but fast memory area. Levels of cache exists.

32/64 bit processors: The amount of data a processor can

process in a clock cycle.

Two major venders

Dual Core,Quad Core , I3 , I5 , I7 X2, X3, X4,

Random Access Memory.

When the operating system loads from disk when you first switch

on the computer, it is copied into RAM.

RAM

Older Computers P4s DDR

Current Computers DDR2

New Computers DDR3

Types

(Double Data Rate)

Read Only Memory (ROM) as the name suggests is a special type of

memory chip that holds software that 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.

ROM

The main circuit board which connects all

the device on a microcomputer; Also called

main board or system board.

Motherboard

Front Panel Connections

Stores data in magnetic disk like medium

Non-volatile mass storage device.

Has very high access time as compared to RAM

(10-20 million ns).

Very cheap as compared to RAM and so large in capacity.

Hard Disk

Types

IDE- Integrated Drive Electronics

(or)

ATA - Advanced Technology Attachment

SATA- Serial Advanced Technology Attachment

Data Cables

Power Connectors IDE To SATA Connector

SATA DATA Cable

Difference Between IDE & SATA

Interface transfer up to 8.3MB/s for ATA-2 and up to 100MB/s (ATA-6).

Transfer rates for Serial ATA begin at 150MB/s.

Big advantage of SATA over ATA is the cabling and

connectors in provides easier routing and better air flow .

Easier to install multiple SATA drivers where as in IDE it has an

jumper setting makes Some difficult tasks when more drives

connected at a time.

Cards

VGA Card

VGA –Video Graphics Adaptor

A modern graphics card is a circuit board with memory and a

dedicated processor.

Converts digital information into the pixels to display it on the

monitor.

On board graphics accelerators share system memory.

Resolution will be less when compare to external card.

Inbuilt VGA

Sound Card

Converts digital data (bits) into analog sound wave and

vice-versa

Has jacks for speaker, microphone, line in, line out and

joysticks

Network Interface Card

Connects PC to LAN (Local Area Network).

Speeds

10Mbps

100Mbps

USB Card:

USB-Universal Serial Bus

To connect larger number of USB Ports to computers

Ports

Serial:

Serial port “serializes” data.

Monitors, Modems etc. use Serial port.

Parallel:

Bits transmitted in parallel.

Used primarily for Printers.

PS/2:

Used to interface keyboards and

pointing devices.

Frees the serial port for other devices.

USB

Data transfer rate 12Mbps/480Mbps.

Multiple devices supported on the bus

Hot pluggable, Plug-and-play.

Provide power through the cable.

Power Cable VGA Cable

USB Cable Network Cable

BIOS

Basic Input Output System

Uses for boot up

Important Functions

Check CMOS Set-up.

POST - Power On Self Test.

Display system setting.

Initiate bootstrap sequence.

System Time/Date.

Boot Sequence.

Plug and Play.

Drive Configuration.

Security.

Power Management

Configuring BIOS

Peripherals

Key Board

Mouse

Scanner

Digital Camera

Input Devices

Output Devices

Monitor

Speakers

Printers

Impact Printer - Dot matrix

Adv. : Inexpensive, Multi-copy forms.

Disadv. : Slow, Loud, Graphics of low Quality

Printer

Non-impact Printer

Inkjet

Thermal

Laser

Adv : Quiet, Can handle graphics, Varieties of fonts.

Disadv. : Expensive.

Modems

Internal Modem

Resides on the expansion board on the slot of the motherboard.

Does not require separate power adapter.

Cheaper than external modem.

Has natural protection inside PC cabinet

External Modem

Resides on a self-contained box outside the PC.

Requires external power adapter.

Connected to PC’s serial port via the cable.

Easy to install and troubleshoot such as resetting the modem.

Expensive than internal modems.

Cabinet

AT Cases

ATX Cases

Types

AT Cases

Older Motherboards (pre-pentium)

Advantages

Well Established standard make.

Easy and cheap design.

Disadvantages

Inefficient cooling.

Not suitable for P-II (& higher).

Newer Motherboards (Pentium based machine)

Advantages

Efficient cooling.

Easy accessibility for upgrades.

I/O are fixed onboard.

ATX Cases

SMPS

Switched-Mode Power Supply

Used to Power Supply for the components

Troubleshooting

• Some simple solutions

Check connections.

Ensure that cards are inserted properly.

Clean the devices.

Check if minimum things needed to boot are present –

motherboard, processor, a full bank of memory, video card and a

drive to boot.

The PC doesn’t start at all

Count the number of beeps.

No beeps - possible problem with BIOS or motherboard.

The PC starts - partially

No signal on the monitor.

Video signal present with error message.

OS starts.

OS does not start - Hard-disk problem.

Hard Drive

– Not bootable : A Hard Drive must be formatted and partitioned

before it can be used.

– Not detected by the BIOS - Check on a different m/c.

It works fine.

It does not work.