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 Unit Output 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 b rain 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)Intel Pentium Sixth generation (Intel Pentium I I & AMD K6)Intel Pentium I AMD K6 Seventh generation (Intel Pentium III, AMD Athlon & Cyrix III)Pentium III AMD AthlonCyrix III Eighth generation (Intel Pentium IV & AMD AthlonXp)Intel Pentium IV Ninth generation (Intel Pentium Extreme Edition & AMD Athlonfx 64bit)

Desktop Processors INTELAMD Pentium, Pentium Pro, Pentium MMX K5, K6 Pentium II, CeleronK6 II, K6 III Pentium III, CeleronAthlon, Duron Pentium IVAthlon 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 ROM RAM 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 pins DDR3-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 to store 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 of bytes

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’ Pit Land