What is a computer ?

• A Computer is an electronic device which takes input through input

devices, processes it and gives the output through output devices.

• It also stores data for further processing.

• Computer works with 0’s & 1’s(Binary).

• Like all electronic devices a computer works with DC power supply.

Block diagram of a computer

ALU

Control Unit

Memory

Input UnitOutput

unit

Types of computers

Components of a computer

• Motherboard

• Processor

• Primary Storage Devices

– RAM (Random Access Memory)

– ROM (Read Only Memory)

• Secondary Storage Devices

– HDD (Hard Disk Drive)

– Optical Drives (CDROM, DVD, etc)

– Floppy Disk drive

• SMPS (Switched Mode Power Supply)

• Input Devices

– Keyboard

– Mouse

• Output Devices

– Monitor

Processors

• It is the brain of the computer

• It is a semi-conductor device

• It contains the complete CPU (Central Processing Unit) in a single chip

• It performs Arithmetic and logical functions

Processor Specifications

• Speed (measured in Hz (Hertz))

• Width (measured in bits, Ex: 16bits,32bits or 64bits)

• FSB Speed (Front Side Bus) (measured in Hz)

• Cache memory (measured in Kbytes/Mbytes)

Types of processors

Slot type processor

Socket type processor

Processor Manufacturers

• Intel

• AMD(Advanced Micro Devices)

• VIA

• Motorola

Generation of the processors

• First Generation(4004, 8008, 8080, 8086, 80186)

• Second generation(80286)

• Third generation (80386)

• Fourth generation (80486)

• Fifth generation (Intel Pentium & AMD K5)

• Sixth generation (Intel Pentium I I & AMD K6)

• Seventh generation (Intel Pentium III , AMD Athlon & Cyrix III)

• Eighth generation (Intel Pentium IV & AMD AthlonXp)

• Ninth generation (Intel Pentium Extreme Edition & AMD Athlonfx64bit)

Desktop Processors

INTEL AMD

Pentium, Pentium Pro, Pentium MMX

K5, K6

Pentium II, Celeron K6 II, K6 III

Pentium III, Celeron Athlon, Duron

Pentium IV Athlon Xp, Sempron

Pentium Dual Core, Pentium Core 2 duo, Pentium Quad core

Athlon Fx, Athlon 64x2, Sempron 64Fx, Opetron

Intel Pentium processors

PENTIUM PROCESSOR PENTIUM – II PROCESSOR

Intel Pentium IV , Core 2 Duo

• vb

Pentium IV

Core 2 duo

Core2 Extreme Quad-Core & Core i7

Primary Storage Classification

PRIMARY STORAGE

ROMRAM

Static RAM Dynamic RAM

RAM(Random Access Memory)

• Primary storage for the CPU.

• Integrated circuits (chips) are used to temporarily store programs,

instructions and data.

• It is a volatile memory (requires power to store the data).

Static Ram (Cache Memory)

• The CPU process data at a very high speed.

• Dynamic RAM cannot match that speed.

• Hence, a special type of RAM called as cache is used.

• Cache memory stores instructions and data which the CPU is

currently working on or may soon need.

• Cache levels:

– The cache memory that is placed inside the actual CPU is called level l cache

(internal cache memory).

– The cache memory located on the die of the CPU is called as level ll cache

(external cache memory).

Cache Location

Types of Dynamic-Ram

SD-RAM(Synchronous dynamic)

168 pins.DDR-RAMS(Double data rate)

184 pins.

DDR2-RAMS(Double data rate)

240 pinsDDR3-RAMS(Double data rate)

240 pins.

Notch Comparison

ROM(Read Only Memory)

– Integrated circuits that are used to permanently store start-up (boot)

instructions and other critical information.

• Types of ROM:

-PROM(Programmable Read Only Memory)

-EPROM(Erasable Programmable Read Only Memory)

-EEPROM (Electrically Erasable Programmable Read Only Memory)

BIOS (Basic input output system)

• During the boot up it performs POST(Power On Self Test)

• Recognizes the hardware devices

• Locates and loads the operating system

• It helps the operating system to access the hardware devices

Bios chip

Components on the motherboard

• Processor slot/socket

• Memory Slots

• Expansion Slots

• I/O Ports

• Chipsets

• IDE / SATA Connectors

• Floppy Drive Connector

• CMOS Battery

• Power Supply connector

• Heat Sink

• Front Panel Connectors

Motherboard

Memory Modules (DIMMS)

SD-DIMM

DDR-DIMM

DDR2-DIMM

Input / Output (I/O) PORTS

MOUSE

KEYBOARD

SERIAL PORT

VGA PORT

AUDIO PORTS

RJ-45

USB PORTS

Back panel connectors:

• PS/2(Personal System v2):

Used to connect keyboard and mouse

• USB(Universal Serial Bus):

Used to connect various USB enabled devices

(Webcam,Pendrive,External Hard disk ,Modems,etc)

• VGA (Visual Graphic Adapter)(15-pin female):

Used to connect display devices like LCD,monitor,projector etc

Back panel connectors:

• Serial port(9-pin male):

Used to connect PC to modems

Also called as Com port

• LAN Port :

Used to connect PC to the Local Area Networks.

Chipsets

• NORTH BRIDGE:

– It controls the processor

and RAM (high speed devices)

– It is placed nearer to the processor

– It also contains graphic processor

– It is also called as GMCH

(Graphic Memory Controller Hub)

• SOUTH BRIDGE :

– It controls low speed devices like I/O ports, slots etc

– It is placed nearer to the slots

– It is also called as IOCH

(Input Output Controller Hub)

IDE and SATA Connectors

IDE and SATA connectors are used to connect Hard Disk, CD-ROM,DVD-ROM etc

IDE(Integrated Drive Electronics)/Enhanced IDE

• IDE/EIDE cables are used to connect the devices to

the connector

SATA(Serial Advanced Technology Attachment)

• SATA cables are used to connect the devices to

the SATA ports

CMOS Battery

• CMOS(Complementary Metal Oxide Semiconductor) RAM is used tostore the date, time, and system configuration

• Battery which powers this memory is called as CMOS Battery

Secondary Storage Devices

• Magnetic storage devices

- Harddisk

- Floppy disk

- Tape drive

- Zip drive

• Optical storage devices

– Compact Disc(CD)

– Digital Versatile Disc(DVD)

– Blu Ray Disc(BRD)

Hard Disk

• Uses magnetic media for storing data

• Non-volatile permanent storage device

• Mass storage devices

• Interfaces used

– IDE / EIDE (Enhanced IDE)

– SATA

IDE Hard-disk Connectors

SATA Hard Disk Connectors

Tracks and Cylinders

Sectors

• Sector is a section of a track which stores a predetermined number ofbytes

Measure hard disk size

• Bit :Â A Bit is a value of either a 0 or 1.

• Byte : 1 Byte = 8 Bits

• 1 Kilobyte (kB) = 1,024 Bytes

• Megabyte (MB) 1MB =1024 KB

• Gigabyte (GB) 1GB = 1024 MB

• Terabyte (TB) 1TB = 1024 GB

• Petabyte (PB) 1PB = 1024 TB

• Exabyte (EB) 1EB = 1024 PB

• Zettabyte (ZB) 1ZB = 1024 EB

Storing Data on a Hard-Disk

• Bits are recorded as positive and negative polarity on magnetic media

CDROM/Combo/DVD/Blu Ray

Optical Drive Back Panel

CD/DVD Surface

• In CD or DVD data is stored in the form of lands and pits

• Land can reflect laser beam and pit will absorb the laser beam

• While reading data if the light emitted by laser is reflected then it is

treated as binary ‘1’ and if laser beam is not reflected then it is

treated as binary ‘0’

PitLand