Hardware Book 1

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Preface

 Nowadays Hardware and networking career is becoming more sought after and the demand for the course is increasing. Expertise in the Hardware field developed over the last two decades feels proud in dedicating this book for the benefit of  the students undergoing Hardware training. Wishes to thanks for read this book.

- MR.M. NAVEEN KUMAR 

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SYLLABUS Unit – 1 Basic of electronic – introduction of computer – types of computer –  computer generation’s – processor introduction.

Unit – 2 Introduction to mother board – introduction to ATX – processor & socket’s – introduction to bios – Disk operation system – Introduction to floppy – Hard disk – CD & DVD.

Unit – 3

Peripherals – Pci slots – External card’s – RAM – Mother   boar block diagram - SMPS. Unit – 4 Troubleshooting – OS installation – Software installation – servicing technique (theory only) – assembling. assembling.

Unit – 5 Introduction to Networking – Types of networking – Topologies –  Scripts – Sharing – Remote connections.

Unit – 6 Computer viruses – types of virus – Computer maintenance.

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Unit – 1 BASIC OF ELECTRONIC : Electronic components are Resistors, Resistors, Capacitor, Diode, PCB board, Transistors, IC’s and socket’s. two-terminal electronic electronic component that produce a voltage across Resistor’s : A resistors is a two-terminal its terminals that is proportional to the electric current passing through it in accordance with ohm’s law V=IR. Refer fig. 1 Resistor diagram

Fig 1 Resistor Capacitor: A capacitor is a passive electronic components consisting of a pair of conductors separated by a dielectric. The capacitors charge a temporary current using circuit. Refer fig 1.1

Refer fig 1.1 Diode: In electronics, a diode is a two terminal components that conduct electric current in only direction. The term usually refers to a semi conductor diode, the most common type today. A vacuum tube diode with two electrodes a plate and a cathode. Fig shown in 1.2

Fig shown in 1.2

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Transistor: A transistor is a semiconductor device used to amplify and switch electronic signals. It is made of solid piece of semiconductor material, which at least three terminals for  connection to external circuit. A Voltage or current applied to one pair of the transistor’s term termin inals als change change the curre current nt flowi flowing ng throug through h anothe anotherr pair pair of term termin inal als. s. Becau Because se the the controlled controlled power can be much more than the controlling controlling i/p power, the transistor provides of  amplification a signal. Some transistors are packaged individually but many more are found embedded in integrated circuits. Refer fig 1.3

Fig 1.3

Introduction to computer A computer is a machine that manipulates data according to a list of instructions. A computer  can also be defined as an electronic machine machine that concepts input data, processes processes in and gives out results. A basic computer consists of three major components: cpu (central processing unit), IO (input and output), and Memory as illustrated.

Fig. 1.4

Computers were initially large machines that could fill entire room. Some were operated using large vacuum tubes that formed the basis of today’s transistors. In order to operator  such machine, punch card were used.1833 Charles Babbage invented his difference engine an early calculator. Together with the punch card design, he created the analytical engine. Regrettably the engine never saw completion due to political issues. Here are some computers that came and went in the history of computing. Some modern examples are also here. ENIAC: ENIAC stood for Electrical Numerical Integrator and Computer. The ENIAC used thousands of vacuum tubes and a punch card mechanism.

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Fig 1.5 Commodore 64: An 8 bit computer introduced in January 1982, the commodore rose to  become the best selling personal computer of all times. Utilising the commodore BASIC   program programmin ming g languag languagee license licensed d from Microsoft Microsoft,, the commodo commodore re was able to host over  10,000 commercial programs. Macintosh: First introduced by apple 1984, the Macintosh was the first computer to use a mouse and graphical user interface (gui) rather than a command line interface. Until the dominance of the IBM Pc, the Macintosh saw use primarily as a desktop publishing tool.

Types of computer 1. Super computer  2. Main frame 3. Work station 4. The personal computer or PC 5. Micro controller  6. Server  Supercomputer: Super computer are fast because they are really many computers working together. Super  computer were introduced in the 1960’s as the world’s most advanced computer. As of    Nove Novemb mber er 200 2008, 8, the fastes fastestt super super comput computer er is the IBM IBM roadru roadrunne nner. r. It has theore theoreti tical cal  processing peak of 1.71 petaflops and has currently peaked at 1.456 petaflops. Mainframe: They are computer where all the processing is done centrally and the user  terminals are called “dumb terminals” since they only input and outputs. Mainfra Mainframes mes are compute computers rs used mainly mainly by large large organiz organizatio ations ns for critica criticall applicat applications ions,, typic typicall ally y bulk bulk data data proces processin sing g such such as census census.. Ex Exam ampl ples: es: banks banks,, airl airline ines, s, insur insuran ances ces companies, and colleges.

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Workstation: Workstation are high-end expensive computer that are made for complex  producers  producers and are intended for one user at a time. Some of the complex producers consist of  scienc science, e, math math and and engin enginee eerin ring g calc calcula ulatio tions ns and are are usefu usefull for comput computer er design design and manufacturing. Workstations are some times improperly named for marketing reasons. Real workstations are not usually sold in retail. Personal computer: Pc is an abbreviation for a personal computer, it is also known as a microcomputer. Its physically characteristics and low cost are appealing and useful for its users. By the early 1970’s people in academic academic or research institutions institutions had the opportunity opportunity for  single-person use of a computer system in interactive mode for extended durations. Microcontroller: They are mini computers that enable the user to store data, do simple commands commands and tasks, with title or no user interaction interaction with the processor. These single circuit devices have minimal memory and program length but can be integrated with other processor  for more complex functionality.

Generation of computer’s Computer Has Five generation of computer’s. They are below. First generation (vacuum tubes) Introduce in 1940-956. Second generation (Transistors) Introduce 1947-1950’s Third generation (integrated circuits (IC)) Introduce in 1964-1971 Fourth generation (microprocessors) Introduce in 1971 – present Fifth generation (present and beyond ) Artificial intelligence

Processor Introduction If example Pentium IV processor contains a million type of transistor in that processor & design designed. ed. First First genera generati tion on proce processo ssorr conta contain in using using 80XXX 80XXX serie series, s, Secon Second d genera generati tion on 802XXX series used, second generation processor’s using a expansion slots type processors. Refer slide

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UNIT – 2 INTRODUCTION INTRODUCTION TO MOTHER BOARD A mother board made up of  PCB  board. If mother board have double circuits Front of  component and back side Circuits can link. Mother board consists of  1. BIOS & CMOS BATTERY 2. CHIPSET 3. PCI SLOTS 4. EXPANSION SLOTS 5. BRIDGE’S 6. PROCESSOR SLOT’S 7. POWER CONNECTOR  8. IDE 9. HARD DISK (HDD) 10. DVD & CD (DVD) Also referred to system board and main board. The motherboard is the foundation of the  pc system. Without the motherboard there would be no computer. computer. Now there are some major   parts of the motherboard motherboard that you need to understand and get very familiar. As always I will try to make this is as simply to understand as possible. So you know what the main idea is of the motherboard now you need to know what its functions are and how it works. Take a look at functions. MOTHER FUNCTIONS

The mother takes care of the entire system task in one way or another. It is a go-between of the system. You will find that almost all component are attached to motherboard in one way or another way. Without the motherboard these system components would be hard  pressed to work. Don’t go cheap on this item and get a good one. When deciding on a case and processors we need to be concerned with designs.

Motherboard formats When it comes to format we all need to pay attention not only to motherboard format but also case format. The formats used today are mainly the ATX, and the AT. These are the only styles you should worry about until things change again and there is a better alternative. AT- this is a design that is fathered after IBM and very common. Though the style is old and not really recommended today. There are many motherboard manufacturers that still make AT boards for those trying to save a buck.

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Baby AT- The baby AT is a smaller than the AT and is found in many cloned IBM machines today. Like the AT it is an old style and is slowly fading out to the ATX. ATX- this is becoming the standard and a nice motherboard. The board is modeled after the  baby AT design except the board is turned 90 degrees in the case allowing much room for big expansion cards. -For those of you that go ahead and throw in a few more dollars and get a ATX motherboard motherboard and the case you will be very pleased. The transition transition is an easy one from the old school style of the AT format to the new ATX. -So what it the Core parts of the motherboard and what do they do for you? Check out some of the components and learn more. INTRODUCTION TO ATX

ATX (Advanced Technology Extended) is a computer form factor specification developed  by Intel in 1995 to improve on previous de facto standards like the AT form factor. It was the first big change in computer case, motherboard, and power supply design in many years, improving standardization and interchangeability of parts. The specification defines the key mechanical dimensions, mounting point, I/O panel, power and connector interfaces between a compute computerr case, case, a motherb motherboard oard,, and a power power supply. supply. With the improvement improvementss it offered, offered, including lower costs, ATX overtook AT completely as the default form factor for new systems within a few years. ATX addressed many of the AT form factor's annoyances that had frustrated system builders. Other standards for smaller boards (including microATX, FlexATX and mini-ITX) usually keep the basic rear layout but reduce the size of the board and the number of  expans expansio ion n slot slot posit position ions. s. In 200 2003, 3, Intel Intel announ announced ced the BTX BTX stand standard ard,, inten intended ded as a replacement for ATX. As of 2009[update], the ATX form factor remains a standard for do-ityourselfers; BTX has however made inroads into pre-made systems.

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PROCESSOR & SOCKET’S 1. CPU (central processing unit) an electronic circuit that can execute computer programs 2. Microprocessor, a CPU on one chip as part of a microcomputer  3. Graphics processing unit (GPU / VPU), a dedicated graphics rendering device for a  personal computer or game console 4. Phys Physics ics proces processin sing g unit unit (PPU (PPU), ), a dedic dedicat ated ed micr micropr oproce ocesso ssorr desig designe ned d to handl handlee the the calculations of physics 5. Digital signal processor, a specialized microprocessor designed specifically for digital signal processing 6. Network processor, a microprocessor specifically targeted at the networking application domain 7. Front end processor, a helper processor for communication between a host computer and other devices 8. Coprocessor  9. Floating point unit 10. Data processor, a system that translates or converts between different data formats 11. Word processor, a computer application used for the production of printable material 12. Audio processor, used in studios and radio stations

8080 Introduced April 1, 1974 Clock rate 2 MHz 0.64 MIPS Bus Width 8 bits data, 16 bits address Enhancement load NMOS logic  Number of Transistors 6,000 Assembly language downwards compatible with 8008. Addressable memory 64 KB Up to 10X the performance of the 8008 Used in the Altair 8800, Traffic light controller, cruise missile Required six support chips versus 20 for the 8008

8085 Introduced March 1976 Clock rate 3 MHz 0.37 MIPS Bus Width 8 bits data, 16 bits address Depletion load NMOS logic  Number of Transistors 6,500 at 3 µm Binary compatible downwards with the 8080. Used Used in To Tole ledo do scales scales.. Also Also was was used used as a comput computer er perip peripher heral al contr controll oller er – modem modems, s, harddisks,printers, etc... CMOS 80C85 in Mars Sojourner, Radio Shack Model 100 portable. High level of integration, operating for the first time on a single 5 volt power supply, from 12 volts previously. Also featured serial I/O,3 maskable interrupts,1 Non-maskable interrupt,1 externally expandable interrupt w/[8259],status,DMA

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Pentium (chronological entry) Introduced March 22, 1993 See main entry [edit] 80486DX4 Introduced March 7, 1994 Clock rates: 75 MHz with 53 MIPS (41.3 SPECint92, 20.1 SPECfp92 on Micronics M4P 256 KB L2) 100 MHz with 70.7 MIPS (54.59 SPECint92, 26.91 SPECfp92 on Micronics M4P 256 KB L2)  Number of Transistors 1.6 million at 0.6 µm Bus width 32 bits Addressable memory 4 GB Virtual memory 64 TB Pin count 168 PGA Package, 208 sq ftP Package Used in high performance entry-level desktops and value notebooks Family 4 model 8 32-bit processors: P5 microarchitecture microarchitecture

Original Pentium Bus width 64 bits System bus clock rate 60 or 66 MHz Address bus 32 bits Addressable Memory 4 GB Virtual Memory 64 TB Superscalar architecture Runs on 5 volts Used in desktops 16 KB of L1 cache P5 – 0.8 µm process technology Introduced March 22, 1993  Number of transistors 3.1 million Socket 4 273 pin PGA processor package Package dimensions 2.16" x 2.16" Family 5 model 1 Variants 60 MHz with 100 MIPS (70.4 SPECint92, 55.1 SPECfp92 on Xpress 256 KB L2) 66 MHz with 112 MIPS (77.9 SPECint92, 63.6 SPECfp92 on Xpress 256 KB L2) P54 – 0.6 µm process technology Socket 5 296/320 pin PGA package  Number of transistors 3.2 million Variants 75 MHz Introduced October 10, 1994 90, 100 MHz Introduced March 7, 1994 P54CQS – 0.35 µm process technology Socket 5 296/320 pin PGA package

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 Number of transistors 3.2 million Variants 120 MHz Introduced March 27, 1995 P54CS – 0.35 µm process technology  Number of transistors 3.3 million 90 mm² die size Family 5 model 2 Variants Socket 5 296/320 pin PGA package 133 MHz Introduced June 12, 1995 150, 166 MHz Introduced January 4, 1996 Socket 7 296/321 pin PGA package 200 MHz Introduced June 10, 1996 [edit] Pentium with MMX Technology P55C – 0.35 µm process technology Introduced January 8, 1997

Intel MMX (instruction set) Socket 7 296/321 pin PGA (pin grid array) package 32 KB L1 cache  Number of transistors 4.5 million System bus clock rate 66 MHz Basic P55C is family 5 model 4, mobile are family 5 model 7 and 8 Variants 166, 200 MHz Introduced January 8, 1997 233 MHz Introduced June 2, 1997 133 MHz (Mobile) 166, 266 MHz (Mobile) Introduced January 12, 1998 200, 233 MHz (Mobile) Introduced September 8, 1997 300 MHz (Mobile) Introduced January 7, 1999

32-bit processors: P6/Pentium M microarchitecture Pentium Pro Introduced November 1, 1995 Precursor to Pentium II and III Primarily used in server systems Socket 8 processor package (387 pins) (Dual SPGA)  Number of transistors 5.5 million Family 6 model 1 0.6 µm process technology 16 KB L1 cache 256 KB integrated L2 cache 60 MHz system bus clock rate Variants 150 MHz

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0.35 µm process technology, or 0.35 µm CPU with 0.6 µm L2 cache  Number of transistors 5.5 million 512 KB or 256 KB integrated L2 cache 60 or 66 MHz system bus clock rate Variants 166 MHz (66 MHz bus clock rate, 512 KB 0.35 µm cache) Introduced November 1, 1995 180 MHz (60 MHz bus clock rate, 256 KB 0.6 µm cache) Introduced November 1, 1995 200 MHz (66 MHz bus clock rate, 256 KB 0.6 µm cache) Introduced November 1, 1995 200 MHz (66 MHz bus clock rate, 512 KB 0.35 µm cache) Introduced November 1, 1995 200 MHz (66 MHz bus clock rate, 1 MB 0.35 µm cache) Introduced August 18, 1997

Pentium II Introduced May 7, 1997 Pentium Pro with MMX and improved 16-bit performance 242-pin Slot 1 (SEC) processor package Slot 1  Number of transistors 7.5 million 32 KB L1 cache 512 KB ½ bandwidth external L2 cache The only Pentium II that did not have the L2 cache at ½ bandwidth of the core was the Pentium II 450 PE. Klamath – 0.35 µm process technology (233, 266, 300 MHz) 66 MHz system bus clock rate Family 6 model 3 Variants 233, 266, 300 MHz Introduced May 7, 1997 Deschutes – 0.25 µm process technology (333, 350, 400, 450 MHz) Introduced January 26, 1998 66 MHz system bus clock rate (333 MHz variant), 100 MHz system bus clock rate for all models after  Family 6 model 5 Variants 333 MHz Introduced January 26, 1998 350, 400 MHz Introduced April 15, 1998 450 MHz Introduced August 24, 1998 233, 266 MHz (Mobile) Introduced April 2, 1998 333 MHz Pentium II Overdrive processor for Socket 8 Introduced August 10, 1998; Engineering Sample Photo 300 MHz (Mobile) Introduced September 9, 1998 333 MHz (Mobile)

Celeron (Pentium II-based) Covington – 0.25 µm process technology Introduced April 15, 1998 242-pin Slot 1 SEPP (Single Edge Processor Package)  Number of transistors 7.5 million Slot 1

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32 KB L1 cache  No L2 cache Variants 266 MHz Introduced April 15, 1998 300 MHz Introduced June 9, 1998 Mendocino – 0.25 µm process technology Introduced August 24, 1998 242-pin Slot 1 SEPP (Single Edge Processor Package), Socket 370 PPGA package  Number of transistors 19 million 66 MHz system bus clock rate Slot 1, Socket 370 32 KB L1 cache 128 KB integrated cache Family 6 model 6 Variants 300, 333 MHz Introduced August 24, 1998 366, 400 MHz Introduced January 4, 1999 433 MHz Introduced March 22, 1999 466 MHz 500 MHz Introduced August 2, 1999 533 MHz Introduced January 4, 2000 266 MHz (Mobile) 300 MHz (Mobile) 333 MHz (Mobile) Introduced April 5, 1999 366 MHz (Mobile) 400 MHz (Mobile) 433 MHz (Mobile) 450 MHz (Mobile) Introduced February 14, 2000 466 MHz (Mobile) 500 MHz (Mobile) Introduced February 14, 2000

Pentium II Xeon (chronological entry) Introduced June 29, 1998 See main entry [edit] Pentium III Katmai – 0.25 µm process technology Introduced February 26, 1999 Improved PII, i.e. P6-based core, now including Streaming SIMD Extensions (SSE)  Number of transistors 9.5 million 512 KB ½ bandwidth L2 External cache 242-pin Slot 1 SECC2 (Single Edge Contact cartridge 2) processor package System Bus clock rate 100 MHz, 133 MHz (B-models) Slot 1 Family 6 model 7 Variants 550 MHz Introduced May 17, 1999 600 MHz Introduced August 2, 1999 533, 600 MHz Introduced (133 MHz bus clock rate) September 27, 1999 Coppermine – 0.18 µm process technology 14

Introduced October 25, 1999  Number of transistors 28.1 million 256 KB Advanced Transfer L2 Cache (Integrated) 242-pin Slot-1 SECC2 (Single Edge Contact cartridge 2) processor package, 370-pin FCPGA (Flip-chip pin grid array) package System Bus clock rate 100 MHz (E-models), 133 MHz (EB models) Slot 1, Socket 370 Family 6 model 8 Variants 500 MHz (100 MHz bus clock rate) 533 MHz 550 MHz (100 MHz bus clock rate) 600 MHz 600 MHz (100 MHz bus clock rate) 650 MHz (100 MHz bus clock rate) Introduced October 25, 1999 667 MHz Introduced October 25, 1999 700 MHz (100 MHz bus clock rate) Introduced October 25, 1999 733 MHz Introduced October 25, 1999 750, 800 MHz (100 MHz bus clock rate) Introduced December 20, 1999 850 MHz (100 MHz bus clock rate) Introduced March 20, 2000 866 MHz Introduced March 20, 2000 933 MHz Introduced May 24, 2000 1000 MHz Introduced March 8, 2000 (Not widely available at time of release) 1100 MHz 1133 MHz (first version recalled, later re-released) 400, 450, 500 MHz (Mobile) Introduced October 25, 1999 600, 650 MHz (Mobile) Introduced January 18, 2000 700 MHz (Mobile) Introduced April 24, 2000 750 MHz (Mobile) Introduced June 19, 2000 800, 850 MHz (Mobile) Introduced September 25, 2000 900, 1000 MHz (Mobile) Introduced March 19, 2001

Intel Core Yonah 0.065 µm (65 nm) process technology Introduced January 2006 533/667 MHz front side bus 2 MB (Shared on Duo) L2 cache SSE3 SIMD instructions 31W TDP (T versions) Family 6, Model 14 Intel Core Duo T2700 2.33 GHz Intel Core Duo T2600 2.16 GHz Intel Core Duo T2500 2 GHz Intel Core Duo T2450 2 GHz Intel Core Duo T2400 1.83 GHz Intel Core Duo T2300 1.66 GHz Intel Core Duo T2050 1.6 GHz Intel Core Duo T2300e 1.66 GHz Intel Core Duo T2080 1.73 GHz 15

Intel Core Duo L2500 1.83 GHz (Low voltage, 15W TDP) Intel Core Duo L2400 1.66 GHz (Low voltage, 15W TDP) Intel Core Duo L2300 1.5 GHz (Low voltage, 15W TDP) Intel Core Duo U2500 1.2 GHz (Ultra low voltage, 9W TDP) Intel Core Solo T1350 1.86 GHz (533 FSB) Intel Core Solo T1300 1.66 GHz Intel Core Solo T1200 1.5 GHz [35]

Dual-Core Xeon LV Sossaman 0.065 µm (65 nm) process technology Introduced March 2006 Based on Yonah core, with SSE3 SIMD instructions 667 MHz frontside bus 2 MB Shared L2 cache Variants 2.0 GHz

32-bit processors: NetBurst microarchitecture Pentium 4 0.18 µm process technology (1.40 and 1.50 GHz) Introduced November 20, 2000 L2 cache was 256 KB Advanced Transfer Cache (Integrated) Processor Package Style was PGA423, PGA478 System Bus clock rate 400 MHz SSE2 SIMD Extensions  Number of Transistors 42 million Used in desktops and entry-level workstations 0.18 µm process technology (1.7 GHz) Introduced April 23, 2001 See the 1.4 and 1.5 chips for details 0.18 µm process technology (1.6 and 1.8 GHz) Introduced July 2, 2001 See 1.4 and 1.5 chips for details Core Voltage is 1.15 volts in Maximum Performance Mode; 1.05 volts in Battery Optimized Mode Power <1 watt in Battery Optimized Mode Used in full-size and then light mobile PCs 0.18 µm process technology Willamette (1.9 and 2.0 GHz) Introduced August 27, 2001 See 1.4 and 1.5 chips for details Family 15 model 1 Pentium 4 (2 GHz, 2.20 GHz) Introduced January 7, 2002 Pentium 4 (2.4 GHz) Introduced April 2, 2002

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0.13 µm process technology Northwood A (1.7, 1.8, 1.9, 2, 2.2, 2.4, 2.5, 2.6, 2.8(OEM),3.0(OEM) GHz) Improved branch prediction and other microcodes tweaks 512 KB integrated L2 cache  Number of transistors 55 million 400 MHz system bus. Family 15 model 2 0.13 µm process technology Northwood B (2.26, 2.4, 2.53, 2.66, 2.8, 3.06 GHz) 533 MHz system bus. (3.06 includes Intel's hyper threading technology). 0.13 µm process technology Northwood C (2.4, 2.6, 2.8, 3.0, 3.2, 3.4 GHz) 800 MHz system bus (all versions include Hyper Threading) 6500 to 10000 MIPS

Pentium Extreme Edition Dual-core microprocessor Enabled Hyper-Threading 800(4x200) MHz front side bus Smithfield – 90 nm process technology (3.2 GHz) Variants Pentium 840 EE – 3.20 GHz (2 x 1 MB L2) Presler – 65 nm process technology (3.46, 3.73) 2 MB x 2 (non-shared, 4 MB total) L2 cache Variants Pentium 955 EE – 3.46 GHz, 1066 MHz front side bus Pentium 965 EE – 3.73 GHz, 1066 MHz front side bus

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INTRODUCTION INTRODUCTION TO BIOS BIOS The Basic Input-Output System (BIOS) is an essential set of routines in a PC, which is stored stored on a chip chip on the the mothe motherbo rboard ard.. It acts acts as an inter interme media diary ry betw between een a comput computer' er'ss hardware and its operating system. Without the BIOS, the PC's operating system would have no way to communicate with, or take control of, the hardware. In other words, the BIOS is a crucial component of any computer. If its options are set incorrectly, the BIOS could slow your computer down by as much as 40%. Unfortunately, as new processors and motherboard chipsets are released, BIOS options continue to get even more confusing. As a result, many seasoned technicians are still baffled by the jargon-laced and confusing options available in a modern computer's BIOS setup program. Many large PC manufacturers such as Dell, HP, Gateway and Micron limit the options available to the end-user in the BIOS, in order to reduce ill-advised "tinkering" and the resulting support calls. As a result, you may not be able to take advantage of some of the advanced settings mentioned here on PCs from these major vendors. It is recommended that you reboot after each individual BIOS setting change to ensure that your system functions normally. If you make numerous changes before rebooting, and your system will no longer boot, you won't know which change is responsible for the failure.

DISK OPERATING SYSTEM When the computer starts, it starts the operating system that takes the control of the machine. An Operating System is a set of programs that help in controlling and managing the Hardware Hardware and the Software resources of a computer system. system. A good operating system should have the following features: 1. Help in the loading of programs and data from external sources into the internal memory  before they are executed. 2. Help programs to perform input/output operations, such as; 1. Print or display the result of a program on the printer or the screen. 2. Store the output data or programs written on the computer in storage device. 3. Communicate the message from the system to the user through the VDU. 4. Accept input from the user through the keyboard or mouse

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As the name suggests, the operating System is used for operating the system or the computer. It is a set of computer programs and also known as DOS (Disk Operating System). The main functions functions of DOS are to manage disk files, allocate allocate system resources resources according according to the the requi requirem rement ent.. DOS DOS provi provides des featu features res essen essenti tial al to contro controll hardwa hardware re devic devices es such such as Keyboard, Screen, Disk Devices, Printers, Modems and programs. Basically, DOS is the medium through which the user and external devices attached to the system communicate with the system. DOS translate the command issued by the user in the format that is understandable by the computer and instruct computer to work accordingly. It also translates the result and any error message in the format for the user to understand.

LOADING DOS The BOOT Record into the computer memory loads DOS. BOOT Record in turn is triggered by ROM program already there in the computer. The system start-up routine of ROM runs a reliability test called Power On Self Test (POST) which which initiali initializes zes the chips chips and the standa standard rd equipme equipment nt attached attached to the the PC, and and check  whether peripherals peripherals connected connected to the computer computer are working working or not. not. Then it it tests the RAM memory memory.. Once this process is over, the ROM bootstra bootstrap p loader attempt attemptss to read the Boot record and if successful, passes the control on to it. The instructions/programs instructions/progr ams in the boot record record then load the rest rest of the program program.. After After the ROM ROM boot strap strap loader loader turns turns the control over to boot record, the boot tries tries to load the DOS into the the memory memory by reading the the two hidden files IBMBIO.COM IBMBIO.COM and IBMDOS.CO IBMDOS.COM. M. If these two are found, they are loaded along with the DOS command interpreter COMMAND.COM. COMMAND.COM contains routines routines that interpret what is typed in through the keyboard in the DOS command command mode. By comparing comparing the input input with with the list of command, command, it acts by executing executing the required routines routines/co /comma mmands nds or by searching searching for the required required routine routine utility utility and loads it into into the memory.

BOOTING BOOT = Build Own Operate Transfer  In computing, booting (also known as "booting up") is a bootstrapping bootstrapping process that starts operating systems when the user turns on a computer system. A boot sequence is the initial set of operations that the computer performs when power is switched on. A computer's central processor can only execute program code found in Read-Only Memo Memory ry (ROM (ROM), ), Rando Random m Acce Access ss Memo Memory ry (RAM (RAM)) or an opera operator tor's 's consol console. e. Mo Moder dern n operating systems and application program code and data are stored on nonvolatile data storage devices, such as hard disk drives, CD, DVD, flash memory cards (like an SD card), USB flash drive, and floppy disk. When a computer is first powered on, it does not have an operating system in ROM or RAM. The computer must initially execute a small program stored in ROM along with the bare minimum of data needed to access the nonvolatile devices from which the operating system programs and data are loaded into RAM.

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The small program that starts this sequence of loading into RAM, is known as a bootstrap loader, bootstrap or boot loader. This small boot loader program's only job is to load other  data and programs which are then executed from RAM. Often, multiple-stage boot loaders are used, during which several programs of increasing complexity sequentially load one after  the other in a process of chain loading.

BOOT LOADERS BIOS OpenBIOS EFI OpenBoot SLOF

Second-stage boot loader The small program is most often not itself an operating system, but only a second-stage  boot loader, such as GRUB, BOOTMGR, BOOTMGR, Syslinux, Syslinux, LILO or NTLDR. It will then be able to load the operating operating system properly, properly, and finally transfer transfer execution to it. The operating system will initialize itself, and may load device drivers that are needed for the normal operation of  the OS. After that it starts loading normal system programs. Some DOS commands: CD CD.. DIR  RD COPY MOVE DIR/AH DIR/AS DIR/AR  DEL RENAME (REN) FORMAT ATTRIB CLS DATE TIME EXIT LABLE MKDIR  MD PROMPT $$ VER  XCOPY

To Go Inner Directory To go outer directory List the directory To remove directory copy any file in commands move any file in commands diplay hidden files display system files display read-only file delete files rename files format drives To change file permission to clear screen to display date To display time exit from dos to display volume lable to make new folder or directory ”” linux To display msdos version copy entire directory

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INTRODUCTION TO FLOPPY A floppy disk is a data storage medium that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive or FDD, [2] Invented by the American information technology company IBM, floppy disks in 8 inch, 5¼ inch and 3½ inch forms enjoyed nearly three decades as a popular and ubiquitous form of data storage and exchange, from the mid-1970s to the late 1990s. While floppy disk drives still have some limited uses, especially with legacy industrial computer equipment, they have now been superseded by USB flash drives, external hard disk drives, CDs, DVDs, Blu Ray discs, memory cards and computer networks. A small motor in the drive rotates the diskette at a regulated speed, while a second motoroperated mechanism moves the magnetic read/write head,(or heads, if a double-sided drive) along the surface of the disk. To write data onto the disk, current is sent through a coil in the head. The magnetic field of the coil magnetizes spots on the disk as it rotates; the change in magnetization encodes the digital data. To read data, the tiny voltages induced in the head coil by the magnetization on the disk are detected, amplified by the disk drive electronics, and sent to the Floppy disk controller. The controller separates the data from the stream of   pulses coming from the drive, decodes the data, tests for errors, and sends the data on to the host computer system. A blank diskette has a uniform featureless coating of magnetic oxide on it. A pattern of  magnetized tracks, each broken up into sectors, is initially written to the diskette so that the diskette controller can find data on the disk. The tracks are concentric rings around the diskette, with spaces between the tracks where no data is written. Other gaps, where no user  data is written, are provided between between the sectors and at the end of the track to allow for slight speed variations in the disk drive. USAGES:

The flexible magnetic disk, commonly commonly called floppy disk , revolutionized computer disk  storage storage for small small systems systems and became became ubiquit ubiquitous ous in the 1980s and 1990s 1990s in their their use with  personal computers and home computers to distribute software, transfer data, and create  backups. In general, different physical sizes of floppy disks are incompatible by definition, and disks can be loaded only on the correct size of drive. There were some drives available with both 3½-inch and 5¼-inch slots that were popular in the transition period between the sizes.

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HARD DISK  A hard-disk drive is non-volatile device used for storage that is located inside the computer case. Like the floppy drive, it holds its data on rotating platters with a magnetic upper exterior which are changed or read by electromagnetic electromagnetic tipped arms that move over the disk as it spins. hard disks come in various speeds. An IDE hard disk spins at 4200rpm and is significantly slower than SATA A particular SATA hard disk has a spindle speed of 7200rpm. A SCSI hard disk (used in servers and high end computers)have a spindle speed of up to 15000rpm Currently, the fastest hard drive would be a SSD (solid state drive) which relies on nonvolatile silicon memory memory chips arranged in arrays to store data. SSDs have nearly no read and write latency and is capable of speeds of 200-300mbps compared to the standard sata which is capable of 40-90mbps. A SSD however can cost 10times the price of a mechanical Hard Disk and store a fraction of the data a mechanical hard disk is capable of. Currently the record is 256GB for SSDs and 1TB for HDDs The setup of a hard disk may include: stand alone master, slave with master present, RAID 0, RAID 1 - 10 RAID Setup: the two most common configurations are RAID 0 and 1 RAID is the abbreviated term for: Redundant Array of Inexpensive Drives. Raid 0 uses the concept of stripping to evenly split data between 2 or more drives. This allows the computer  to access multiple drives simultaneously simultaneously to increase data transfer rate and response time. The disadvantages of this setup is reliability. If one of the drives fail -- your data is gone. RAID 1, is the setup in which 2 or more disks are used to create copies of each other assuring no data loss if one or more drives fail in the array. Performance wise, there is no gain. The most cost effective purchase would be for a 500GB internal HD in the SATA format which will run about 120$. 25 cent per MB is the current sweat spot for purchase, anything higher or lower will cost more per MB.

HDD Formatting Modern HDDs, such as SAS[29] and SATA[30] drives, appear at their interfaces as a contiguous contiguous set of logical blocks; typically typically 512 bytes long but the industry is in the process of  changing to 4,096 byte logical blocks.[31] The process of relating these logical blocks to their   physical location on the HDD is called low level formatting which is usually performed at the factory and is not normally changed in the field.[32] High level formatting then writes the file system structures structures into selected selected logical blocks to make the remaining logical blocks available to the host OS and its applications

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CD & DVD”S A CD-RW (Compact Disc-Rewritable) is a rewritable optical disc format. Known as CDErasable (CD-E) during its development, CD-RW was introduced in 1997, and was preceded  by the CD-MO, which was never officially released, in 1998. CD-RW discs require a more sensitive laser optics. Also, CD-RWs cannot be read in some CD-ROM drives built prior to 1997. This is why CD-ROM drives of the age must bear a "MultiRead" certification to show compatibility. CD-RW discs need to be blanked before reuse. Different blanking methods can be used, including "full" blanking in which the entire surface of the disc is cleared, and "fast" blanking in which only meta-data areas are cleared: PMA, TOC and pregap, comprising comprising a few percent of the disc. Fast blanking is much quicker, and is usually sufficient to allow rewriting the disc. Full blanking removes traces of the former data, often for confidentiality. It may be possible to recover data from full-blanked CD-RWs with specialty data recovery equipment[citation needed]; however, this is generally not used except by government agencies due to cost. CD-RW also have a shorter rewriting cycles life (ca. 1,000) compared to virtually all of the  previously exposed types storage of media (typically well above 10,000 or even 100,000), something which however is less of a drawback considering that CD-RWs are usually written and erased in their totality, and not with repeated small scale changes, so normally wear  leveling is not an issue. Their ideal usage field is in the creation of test disks, temporary short or mid-term backups, and in general, where an intermediate solution between online and offline storage schemes is required.

WORK: All CDs and DVDs work by virtue of marks on the disc that appear darker than the  background.  background. These are detected by shining a laser on them and measuring measuring the reflected light. In the case of molded CDs or DVDs, such as those bought in music or video stores, these marks are physical “pits” imprinted into the surface of the disc. In CD-Recordable (CD-R) discs, a computer’s writing laser creates permanent marks in a layer of dye polymer in the disc. CD-Rewritable (CD-RW) discs are produced in a similar fashion, except that the change to the recording surface is reversible. The key is a layer of phase-change material, an alloy composed of silver, indium, antimony and tellurium. Unlike most solids, this alloy can exist in either of two solid states: crystalline crystalline (with atoms closely packed in a rigid and organized array) or amorphous (with atoms in random positions). The amorphous state reflects less light than the crystalline one does. When heated with a laser to about 700 degrees Celsius, the alloy switches from the original crystalline phase to the amorphous state, which then appears as a dark spot when the disc is  played back. These spots can be erased using the same laser (at a lower power) to heat the material to a temperature of 200 degrees C or so; this process returns the alloy to its crystalline state. Most CD-RW makers suggest that one disc can be overwritten up to 1,000 times and will last about 30 years.

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Prior Prior to the the introd introduct uctio ion n of the the CD-R CD-RW W techn technolo ology gy,, a standa standard rd for magne magnetoto-opt optic ical al recordable and erasable CDs called CD-MO was introduced in 1988 and set in the Orange Book, part 1, and was basically a CD with a magneto-optical recording layer. The CD-MO standard also allowed for an optional non-erasable zone on the disk, which could be read by normal CD-ROM reader units. Data recording (and erasing) was achieved by heating the magneto-optical layer's material (eg. DyFeCo DyFeCo or less often TbFeCo or GdFeCo) up to its Curie point thus erasing all previous data and then using a magnetic field to write the new data, in a manner essentially identical to Sony's MiniDisc and other magneto-optical formats. Reading of the discs relied on the Kerr  effect. This was also the first major flaw of this format: it could only be read in special drives and was physically incompatible with non magneto-optical enabled drives, in a much more radical way than the later CD-RWs.

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UNIT-3 A peripheral is a device attached to a host computer but not part of it, and is more or less dependent on the host. It expands the host's capabilities, but does not form part of the core computer architecture. Examples are computer printers, image scanners, tape drives, microphones, loudspeakers, webcams, and digital cameras. Overview: Whether something is a peripheral or part of a computer is not always clearly demarcated. demarcated. A video capture card inside a computer case is not part of the core computer but is contained in the case. However, whether something can be considered a peripheral or not is a trivial matter of nomenclature, and is not a significant issue

Common Peripheral’s Devices 

Storage  Input (a. input devices) Out put devic devices es (a. Outp Output ut devic devicee b. Displ Display ay devic devicee c. Graph Graphic ical al output output devic devicee d.  Out Computer display)

STORAGE Computer data storage, often called storage or memory, refers to computer components and recor recordin ding g media media that that retai retain n digit digital al data data used used for for comp computi uting ng for some some inte interva rvall of time time.. Computer data storage provides one of the core functions of the modern computer, that of  information information retention. It is one of the fundamental components components of all modern computers, and coupled with a central processing unit (CPU, a processor), implements the basic computer  model used since the 1940s. In contemporary usage, memory usually refers to a form of semiconductor storage known as random-access memory (RAM) and sometimes other forms of fast but temporary storage. Similarly, storage today more commonly refers to mass storage — optical discs, forms of  magnetic storage like hard disk drives, and other types slower than RAM, but of a more  permanent nature. Historically, memory and storage were respectively called main memory and secondary storage (or auxiliary storage). Auxiliary storage (or auxiliary memory units) was also used to represent represent memory which was not directly directly accessible by the CPU (secondary (secondary or tertiary storage). The terms internal memory and external memory are also used. The conte The contemp mpora orary ry disti distinc ncti tions ons are helpf helpful, ul, becaus becausee they they are are also also funda fundame menta ntall to the the architecture of computers in general. The distinctions also reflect an important and significant technical difference between memory and mass storage devices, which has been blurred by the the histo historic rical al usage usage of the the term term stora storage. ge. Never Neverthe thele less, ss, this this artic article le uses uses the tradi traditio tional nal nomenclature.

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Purpose of storage

Many different forms of storage, based on various natural phenomena, have been invented. So far, no practical universal storage medium exists, and all forms of storage have some drawbacks. Therefore a computer system usually contains several kinds of storage, each with an individual purpose. A digital computer represents data using the binary numeral system. Text, numbers, pictures, audio, and nearly any other form of information can be converted into a string of bits, or   binary digits, each of which has a value of 1 or 0. The most common unit of storage is the  byte, equal to 8 bits. A piece of information can be handled by any computer whose storage space is large enough to accommodate the binary representation of the piece of information, or simply data. For example, using eight million bits, or about one megabyte, a typical computer could store a short novel. Traditionally Traditionally the most important part of every computer is the central processing processing unit (CPU, or simply a processor), because it actually operates on data, performs any calculations, and controls all the other components. Primary Memory

Primary Primary storage (or main memory or internal memory), memory), often referred to simply as memory, memory, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required. Any data actively operated operated on is also stored there in uniform manner. Historically, early computers used delay lines, Williams tubes, or rotating magnetic drums as  primary storage. By 1954, those unreliable methods were mostly replaced by magnetic core memory. Core memory remained dominant until the 1970s, when advances in integrated circuit technology allowed semiconductor memory to become economically competitive. This led This led to moder modern n random random-ac -acces cesss memo memory ry (RAM (RAM). ). It is small small-si -sized zed,, light light,, but quite quite expensive at the same time. (The particular types of RAM used for primary storage are also volatile, i.e. they lose the information when not powered). As shown in the diagram, traditionally there are two more sub-layers of the primary storage,  besides main large-capacity

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RAM: Secondary storage Secondary Secondary storage (or external memory) memory) differs from primary storage in that it is not directly directly acces accessib sible le by the the CPU. CPU. Th Thee comp compute uterr usual usually ly uses uses its its input input/ou /outpu tputt channe channels ls to acce access ss secondary storage and transfers the desired data using intermediate area in primary storage. Secondary storage does not lose the data when the device is powered down—it is nonvolatile. Per unit, it is typically also two orders of magnitude less expensive than primary storage. Consequently, modern computer systems typically have two orders of magnitude more secondary storage than primary storage and data is kept for a longer time there.

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In modern computers, hard disk drives are usually used as secondary storage. The time taken to access a given byte of information information stored on a hard disk is typically a few thousandths of a second, or milliseconds. By contrast, the time taken to access a given byte of information stored in random access memory is measured in billionths of a second, or nanoseconds. This illustrates illustrates the very significant significant access-time access-time difference which distinguishes solid-state memory from rotating magnetic storage devices: hard disks are typically about a million million times slower  than memory. Rotating optical storage devices, such as CD and DVD drives, have even longer access times. With disk drives, once the disk read/write head reaches the proper   placement and the data of interest rotates under it, subsequent data on the track are very fast to access. As a result, in order to hide the initial seek time and rotational latency, data are transferred to and from disks in large contiguous blocks. The secondary storage is often formatted according to a file system format, which provides the abstraction necessary to organize data into files and directories, providing also additional information (called metadata) describing the owner of a certain file, the access time, the access permissions, and other information. INPUT DEVICES

An input device is any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing processing system (such as a computer). Input and output devices make up the hardware interface between a computer as a scanner or 6DOF controller. Many input devices can be classified according to: Modality of input (e.g. mechanical motion, audio, visual, etc.) The input is discrete (e.g. key presses) or continuous (e.g. a mouse's position, though digitized into a discrete quantity, is fast enough to be considered continuous) The number of degrees of freedom involved (e.g. two-dimensional two-dimensional traditional traditional mice, or threedimensional navigators designed for CAD applications) Pointing devices, which are input devices used to specify a position in space, can further be classified according to: Whether the input is direct or indirect. With direct input, the input space coincides with the display space, i.e. pointing is done in the space where visual feedback or the cursor appears. Touch screens and light pens involve direct input. Examples Examples involving indirect input include the mouse and trackball. Whether the positional information is absolute (e.g. on a touch screen) or relative (e.g. with a mouse that can be lifted and repositioned) Output devices

An output device is any piece of computer hardware equipment used to communicate the resul results ts of data data proce processi ssing ng carri carried ed out by an infor informa mati tion on proces processin sing g syst system em (such (such as a computer) to the outside world.

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In computing, input/output, or I/O, refers to the communication between an information  processing  processing system (such as a computer), computer), and the outside world. Inputs Inputs are the signals or data sent to the system, and outputs are the signals or data sent by the system to the outside. PCI (peripheral component interface)

Conventional PCI (part of the PCI Local Bus standard and often shortened to PCI) is a computer bus for attaching hardware devices in a computer. These devices can take either the form of an integrated circuit fitted onto the motherboard itself, called a planar device in the PCI specification, or an expansion card that fits into a slot. The name PCI is an initialism formed from Peripheral Component Interconnect. The PCI Local Bus is common in modern PCs, where it has displaced ISA and VESA Local Bus as the standard expansion bus, and it also appears in many other computer types. Despite the availability of faster interfaces such as PCI-X and PCI Express, conventional PCI remains a very common interface. The PCI specification covers the physical size of the bus (including the size and spacing of  the circuit board edge electrical contacts), electrical characteristics, bus timing, and protocols. The specification can be purchased from the PCI Special Interest Group (PCI-SIG). Typical PCI cards used in PCs include: network cards, sound cards, modems, extra ports such as USB or serial, TV tuner cards and disk controllers. Historically video cards were typically PCI devices, but growing bandwidth bandwidth requirements soon outgrew the capabilities of PCI. PCI video cards remain available for supporting extra monitors and upgrading PCs that do not have any AGP or PCI Express slots.[1] Many devices traditionally provided on expansion cards are now commonly integrated onto the motherboard itself, itself, meaning that modern PCs often have no cards fitted. However, PCI is still still used for certain certain speciali specialized zed cards, cards, although although many many tasks tasks traditi traditional onally ly perform performed ed by expansion cards may now be performed equally well by USB devices. PCI (Peripheral Component Interconnect) was immediately put to use in servers, replacing MCA and EISA as the server expansion bus of choice. In mainstream PCs, PCI was slower to replace VESA Local Bus (VLB), and did not gain significant market penetration until late 1994 1994 in seco second nd-g -gen ener erat atio ion n Pent Pentiu ium m PCs. PCs. By 1996 1996 VLB VLB was was all all but but exti extinc nct, t, and and manufacturers had adopted PCI even for 486 computers.[2] EISA continued to be used alongside PCI through 2000. Apple Computer adopted PCI for professional Power Macintosh comput computers ers (repl (replaci acing ng NuBu NuBus) s) in mid-1 mid-1995 995,, and the consu consume merr Perfo Perform rmaa produc productt line line (replacing LC PDS) in mid-1996. Later revisions of PCI added new features and performance improvements, including a 66 MHz 3.3 V standard and 133 MHz PCI-X, and the adaptation adaptation of PCI signaling to other form factors. Both PCI-X 1.0b and PCI-X 2.0 are backward compatible with some PCI standards. The PCI-SIG introduced the serial PCI Express in 2004. At the same time they rechristened PCI PCI as Conv Conven enti tion onal al PCI. PCI. Sinc Sincee then then,, moth mother erbo boar ard d manu manufa fact ctur urer erss have have incl includ uded ed  progressively fewer Conventional PCI slots in favor of the new standard.

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EXPANSION SLOT

The expansion card (also expansion board, adapter card or accessory card) in computing computing is a  printed  printed circuit board that can be inserted into an expansion slot of a computer motherboard to add functionality to a computer system. One edge of the expansion card holds the contacts (the edge connector) that fit exactly into the slot. slot. They They establi establish sh the electric electrical al contact contact between between the electro electronics nics (mostly (mostly integrat integrated ed circuits) on the card and on the motherboard. Connectors mounted on the bracket allow the connection of external devices to the card. Depending on the form factor of the motherboard and case, around one to seven expansion cards can be added to a computer system. In the case of a backplane system, up to 19 expansion cards can be installed. There are also other factors involved in expansion card capacity. For example, most graphics cards on the market as of 2010 are dual slot graphics cards, using the second slot as a place to put an active heat sink with a fan. Some cards are "low-profile" cards, meaning that they are shorter than standard cards and will fit in a lower height computer chassis. (There is a "low profile PCI card" standard[1] that specifies specifies a much smaller bracket and board area). The group of expansion cards that are used for external connectivity, connectivity, such as a network, SAN or modem card, are commonly referred referred to as input/output cards (or I/O cards). The primary purpose purpose of an expansion card is to provide or expand on features features not offered by the motherboard. For example, the original IBM PC did not provide graphics or hard drive capability capability as the technology technology for providing that on the motherboard motherboard did not exist. In that case, a graphi graphics cs expan expansi sion on card card and an ST-50 ST-506 6 hard hard disk disk contr controll oller er card card provid provided ed graphi graphics cs capability and hard drive interface respectively. In the case of expansion of on-board capability, a motherboard may provide a single serial RS232 port or Ethernet port. An expansion card can be installed to offer multiple RS232  ports or multiple and higher bandwidth Ethernet ports. In this case, the motherboard provides  basic functionality but the expansion card offers additional or enhanced ports.

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expansion slot shown in fig.,

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RAM An early early type type of wides widespre pread ad writ writabl ablee random random-ac -acce cess ss memo memory ry was was the the magne magneti ticc core core memory, developed from 1949 to 1952, and subsequently used in most computers up until the development of the static and dynamic integrated RAM circuits in the late 1960s and early 1970s. Before this, computers used relays, delay line/delay memory, or various kinds of  vacuum vacuum tube tube arran arrangem gement entss to impl impleme ement nt "mai "main" n" memo memory ry funct function ionss (i.e (i.e., ., hun hundre dreds ds or  thousands of bits), some of which were random access, some not. Latches built out of  vacuum tube triodes, and later, out of discrete transistors, were used for smaller and faster  memories such as random-access register banks and registers. Prior to the development of  integ integrat rated ed ROM ROM circu circuit its, s, perma permane nent nt (or readread-onl only) y) random random-a -acce ccess ss memo memory ry was was often often constructed using semiconductor diode matrices driven by address decoders. RAM disks Software can "partition" a portion of a computer's RAM, allowing it to act as a much faster  hard drive that is called a RAM disk. A RAM disk loses the stored data when the computer is shut down, unless memory is arranged to have a standby battery power source. DDR AND SD RAM

Double data rate synchronous dynamic random access memory (DDR SDRAM) SDRAM) is a class of  memory integrated circuits used in computers. Compared to single data rate (SDR) SDRAM, the DDR SDRAM interface makes higher  transfer rates possible by more strict control of the timing of the electrical data and clock  signals. Implementations often have to use schemes such as phase-locked loops and selfcalibration to reach the required timing accuracy.[1][2]The interface uses double pumping (transferring data on both the rising and falling edges of the clock signal) to lower the clock  frequency. One advantage of keeping the clock frequency down is that it reduces the signal integrity requirements on the circuit board connecting the memory to the controller. The name "double data rate" refers to the fact that a DDR SDRAM with a certain clock frequency achieves nearly twice the bandwidth of a single data rate (SDR) SDRAM running at the same clock frequency, due to this double pumping. With data being transferred 64 bits at a time, DDR SDRAM SDRAM gives a transfer rate of (memory (memory  bus clock rate) × 2 (for dual rate) × 64 (number of bits transferred) transferred) / 8 (number of bits/byte). bits/byte). Thus, with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of  1600 MB/s. "Beginning "Beginning in 1996 and concluding in June 2000, JEDEC developed the DDR (Double Data Rate) SDRAM specification (JESD79)."[3] JEDEC has set standards for data rates of DDR  SDRAM, SDRAM, divided into two parts. The first specification is for memory chips, and the second is for memory modules. modules. DDR SDRAM (sometimes referred to as DDR1 SDRAM) SDRAM) has been superseded by DDR2 SDRAM and DDR3 SDRAM.

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DDR SERIES

OLD SD RAM

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MOTHER BOARD A motherboard is the central printed circuit board (PCB) in many modern computers and holds many of the crucial components of the system, while providing connectors for other   peripherals. The motherboard is sometimes alternatively known as the main board, system  board, or, on Apple computers, computers, the logic board.[1] It is also sometimes casually casually shortened to mobo During the late 1980s and 1990s, it became economical to move an increasing number of   peripheral functions onto the motherboard (see below). In the late 1980s, motherboards began to include single ICs (called Super I/O chips) capable of supporting a set of low-speed  peripherals: keyboard, mouse, floppy disk drive, serial ports, and parallel ports. As of the late 1990s, many personal computer motherboards supported a full range of audio, video, storage, and networking functions without the need for any expansion cards at all; higher-end systems for 3D gaming and computer computer graphics typically retained only the graphics card as a separate component. Most computer motherboards produced today are designed for IBM-compatible computers, which currently account for around 90% of global PC sales A motherboard, like a backplane, provides the electrical connections by which the other  components of the system communicate, but unlike a backplane, it also connects the central  processing unit and hosts other subsystems and devices. A typica typicall desktop desktop compute computerr has its micropr microproces ocessor, sor, main main memory memory,, and other other essentia essentiall compone components nts connecte connected d to the motherb motherboard oard.. Other Other componen components ts such as external external storage, storage, controllers for video display and sound, and peripheral devices may be attached to the motherboard as plug-in cards or via cables, although in modern computers it is increasingly common to integrate some of these peripherals into the motherboard itself. An important component of a motherboard is the microprocessor's microprocessor's supporting chipset, which   provides the supporting interfaces between the CPU and the various buses and external compone components. nts. This chipset chipset determi determines, nes, to an extent, extent, the features features and capabili capabilitie tiess of the motherboard. Modern motherboards include, at a minimum: Sockets

(or slots) in which one or more microprocessors may be installed. Slots into which the system's main memory is to be installed (typically in the form of  DIMM modules containing DRAM chips) A chipset which forms an interface between the CPU's front-side bus, main memory, and  peripheral buses  Non-volatile memory chips (usually Flash ROM in modern motherboards) containing the system's firmware or BIOS A clock generator which produces the system clock signal to synchronize the various components Slots for expansion cards (these interface to the system via the buses supported by the chipset)

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Power

connectors, which receive electrical power from the computer power supply and distribute it to the CPU, chipset, main memory, and expansion cards

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Additionally, nearly all motherboards include logic and connectors to support commonly used input devices, such as PS/2 connectors for a mouse and keyboard. Early personal computers computers such as the Apple II or IBM PC included only this minimal minimal peripheral support on the the moth motherb erboar oard. d. Occa Occasio sional nally ly video video inter interfac facee hardwa hardware re was was also also integr integrat ated ed into into the motherboard; motherboard; for example, example, on the Apple II and rarely on IBM-compatible IBM-compatible computers computers such as the IBM PC Jr. Additional Additional peripherals such as disk controllers controllers and serial ports were provided as expansion cards. Given the high thermal design power of high-speed computer CPUs and components, modern motherboards nearly always include heat sinks and mounting points for fans to dissipate excess heat. CPU SOCKETS

A CPU socket or slot is an electrical component that attaches to a printed circuit board (PCB) and is designed to house a CPU (also called a microprocessor). It is a special type of  integrated circuit socket designed for very high pin counts. A CPU socket provides many funct function ions, s, incl includi uding ng a phy physi sical cal struct structure ure to suppor supportt the CPU, CPU, suppor supportt for a heat heat sink, sink, facil facilit itati ating ng repla replacem cement ent (as well well as reduci reducing ng cost cost), ), and most most impor importa tantl ntly, y, formi forming ng an electrical electrical interface both with the CPU and the PCB. CPU sockets can most often be found in most desktop and server computers (laptops typically typically use surface mount CPUs), particularly particularly those based on the Intel x86 architecture on the motherboard. A CPU socket type and motherboard chipset must support the CPU series and speed. Generally, with a newer AMD microprocessor, you need only select a motherboard that supports the CPU and not be concerned with the chipset. INTERGRATED PERIPHERALS

With the steadily declining costs and size of integrated circuits, it is now possible to include support for many peripherals on the motherboard. By combining many functions on one PCB, the physical size and total cost of the system may be reduced; highly integrated motherboards are thus especially popular in small form factor and budget computers. For example, the ECS RS485M-M, a typical modern budget motherboard for computers  based on AMD processors, has on-board support for a very large range of peripherals

      

disk controllers for a floppy disk drive, up to 2 PATA drives, and up to 6 SATA drives (including RAID 0/1 support) integrated ATI Radeon graphics controller supporting 2D and 3D graphics, with VGA and TV output integrated sound card supporting 8-channel (7.1) audio and S/PDIF output Fast Ethernet network controller for 10/100 Mbit networking USB 2.0 controller supporting up to 12 USB ports IrDA controller for infrared data communication (e.g. with an IrDA-enabled cellular   phone or printer) temperature, temperature, voltage, and fan-speed sensors that allow software to monitor the health of computer components

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TEMPERATURE AND RELIABILITY

Motherboards Motherboards are generally air cooled with heat sinks often mounted on larger chips, such as the Northbridge, in modern motherboards. If the motherboard is not cooled properly, it can cause the computer to crash. Passive cooling, or a single fan mounted on the power supply, was sufficient for many desktop computer CPUs until the late 1990s; since then, most have required CPU fans mounted on their heat sinks, due to rising clock speeds and power  consumption. Most motherboards have connectors for additional case fans as well. Newer  moth motherb erboar oards ds have have integ integrat rated ed temper temperatu ature re sensor sensorss to detect detect mothe motherbo rboard ard and and CPU CPU temperatures, and controllable fan connectors which the BIOS or operating system can use to regu regula late te fan fan spee speed. d. Some Some com compute puters rs (whi (which ch typi typica call lly y have have high high-p -per erfo form rman ance ce microprocessors, large amounts of RAM, and high-performance video cards) use a watercooling system instead of many fans. BIOS

Mothe Motherbo rboar ards ds contai contain n some some non non-vo -vola lati tile le memo memory ry to init initial ialize ize the the syste system m and load load an operating system from some external peripheral device. Microcomputers such as the Apple II and IBM PC used ROM chips, mounted in sockets on the motherboard. At power-up, the central processor processor would load its program counter with the address of the boot ROM and start executin executing g ROM instruct instructions ions,, display displaying ing system system informa information tion on the screen screen and running running memory checks, which would in turn start loading memory from an external or peripheral device (disk drive). If none is available, then the computer can perform tasks from other  memory stores or display an error message, depending on the model and design of the computer and version of the BIOS. Most modern motherboard designs use a BIOS, stored in an EEPROM chip soldered to the motherboard, to bootstrap the motherboard. (Socketed BIOS chips are widely used, also.) By  booting the motherboard, the memory, circuitry, and peripherals are tested and configured. This process is known as a computer Power-On Self Test (POST) and may include testing some of the following devices: floppy drive network controller  CD-ROM drive DVD-ROM drive SCSI hard drive IDE, EIDE, or SATA hard disk  External USB memory storage device

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Block diagram

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SMPS A switched-mode power supply (switching-mode power supply, SMPS, or simply switcher) is an electronic power supply that incorporates a switching regulator in order to be highly efficient efficient in the conversion of electrical power. Like other types of power supplies, an SMPS transfers power from a source like the electrical power grid to a load (e.g., a personal comput computer) er) whil whilee conve converti rting ng volta voltage ge and and curre current nt chara characte cteri rist stics ics.. An SMPS SMPS is usual usually ly employed employed to efficiently efficiently provide a regulated regulated output voltage, typically at a level different from the input voltage. Unlike a linear power supply, the pass transistor of a switching mode supply switches very quickly (typically between 50 kHz and 1 MHz) between full-on and full-off states, which minimizes wasted energy. Voltage regulation is provided by varying the ratio of on to off  time. In contrast, a linear power supply must dissipate the excess voltage to regulate the output. This higher efficiency is the chief advantage of a switch-mode power supply. Swit Switch ching ing regul regulat ators ors are used used as replac replacem ement entss for the the linea linearr regula regulator torss when when highe higher  r  efficiency, smaller size or lighter weight are required. They are, however, more complicated, their switching currents can cause electrical noise problems if not carefully suppressed, and simple designs may have a poor power factor.

A modern computer power supply is a switch with on and off supply designed to convert 110-240 V AC power from the mains supply, to several output both positive (and historically negative) negative) DC voltages in the range + 12V,-12V,+5V,+5VBs 12V,-12V,+5V,+5VBs and +3.3V. The first generation generation of computers power supplies were linear devices, but as cost became a driving factor, and weight became important, switched mode supplies are almost universal.

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ATX shown in fig;

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UNIT – 4 TROUBLESHOOTING 1. RAM PROBLEM:  System give 3 short beep’s like 1-1-1  No display means ( monitor cannot receive signal from mother board ) BLUE SCREEN ERROR  System alt ( hang ) Solve:

Remove the ram from ram slot clear the ram.  If no Display change the ram slot. Or change the ram BLUE SCREEN ERROR did u see if ram memory failure CHANGE THE RAM If system alt cannot boot remove and clear the ram and slot also clear temp files. 

2. PROCESSOR PROBLEM:

if processor failure you can receive 5 short beep 1 1 1 1 1 – 1 1 1 1 1  No Display also Capacitor problem. Solve:

Receive 5 beep change the processor (ALSO NO DISPLAY)  If capacitor problem change that related capacitor  3. BIOS PROBLEM: System

can restart System cannot Start Keyboard halt etc.,  hard disk or device detection problem.  boot device problem also. Solved: Clear

the CMOS or BIOS using jumper’s config the bios jumper’s.

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4. NO DISPLAY PROBLEM: Change

the ram Change the processor  Petrol washes the mother board Clear the bios Check the power supply in and out using multimeter  Check southern bridge Check PCI slots Check IDE & FDD connector’s Check the capacitor’s check fan & heat sink.

OPERATING SYSTEM INSTALLATION XP: First

check the bios booting device’s DVD & HARD DISK  nd Assign the 1, 2, 3  booting device’s. Insert “WINDOWS XP” in to the DVD or CD Drive In screen “PRESS ANY KEY TO CONTINUE. . . . .” Press any key in key board. Enter to “XP INSTALLATION” will start. Press “Enter” to Welcome screen  Press “F8 - I AGREE” To continue for license agreement. IF new hard disk they to enter to the partition if no hard disk is old ask this question “C:\WINDOWS\SYSTEM32\” press “ENTER TO CONTINUE”. You will enter in partition option’s After you create partition go to c:\ press ENTER  He ask 4 question’s Like this QUICK NTFS, QUICK FAT, NTFS, FAT, Leave changes If put NTFS quick format. After 39minute’s will start Click NEXT Click Next for Language and keyboard Enter “PRODUCT ID” Click Next Enter date and Time zone. Click Next Enter Network option click Next After complete the Setup in Welcome screen in Windows XP. Then OPERATING SYSTEM INSTALLATION COMPLETED

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SOFTWARE INSTALLATION Driver Installation Insert Mother board CD in to DVD or CD Drive if some CD’s can auto play installation. I old type installation is .inf installation. Software are Three types I Package II Application III programming IV System software

Various types of computer software are used to simplify the operations and applications of  comput computer er progr program ams. s. Comp Compute uterr softw softwar aree enable enabless the the comp compute uterr syst system em to perfo perform rm in accordance with the given tasks. Computer software involves all types of software related applications. Electronic media content is also explained by the computer software. Classification of Computer Software Diff Differ eren entt type typess of comp comput uter er soft softwa ware re are are avai availa labl blee in the the glob global al comp comput uter er mark market et.. Programming Programming software, system software and application software are the three main types of  computer software used in computer networking. System software is the most commonly used variety types of software. System software offers a protective shield to all software applications. It also provides support to the physical components of computers. System software coordinates coordinates all external devices of computer system like printer, keyboard, displays etc.

Progr Program amme mers rs use the progra programm mming ing soft softwa ware re to devel develop op the the progr program ammi ming ng langu language agess necessary to run computer software. Compliers, interpreters, linkers and text editors are some of the basic tools used in programming software. Application software is used for commercial purpose. The application software is widely used in educational, business and medical fields. Computer games are the most popular forms of applicat application ion softwar software. e. Industri Industrial al automat automation, ion, database databases, s, business business softwar softwaree and medical medical software prove to be of great help in the respective fields. Educational software is widely used in educational institutes across the globe.

Functioning of Computer Software

Computer software works through computer programming. The whole process runs like a chain chain react reaction ion.. Trans Transfe ferr of comma commands nds initi initiate atess the the chain chain.. Machi Machine ne code code genera generate ted d by computer software ends the entire process.

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UNIT -5 INTRODUCTION INTRODUCTION TO NETWORKING What is a Network? A computer network is simply two or more computers connected together so they can exchange information. A small network can be as simple as two computers linked together by a single cable.

Building a Simple Network 

Most networks use hubs to connect computers together. A large network may connect thousands of computers and other devices together.

What Can I do With a Simple Network? Without a network, you can access resources only on your own computer. These resources may be devices in your computer, such as a folder or disk drive, or they may be connected to your computer, such as a printer or CD-ROM drive. These devices, accessible only to you, are local resources.  Networking allows you to share resources among a group of computer users.

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Sharing Files and Drives

If your your comput computers ers are connec connecte ted d to a netw network ork,, each each comp compute uterr can make make its its resour resources ces available to other computers in your office by sharing them over the network. Instead of  working in isolation as you do on a single computer not linked to a network, you can work  collectively, within a system that shares resources among a group of computer users. Each computer on your network can share folders, entire disk drives, or a CD-ROM drive. Then other computers on your network can access documents and other files stored in the folders and on the drives. Instead of copying a document to a diskette and giving it to another   person to view, anyone can open and view the document using the network. If you want to view the company's annual report stored on a co-worker's computer, you can use the network to access the document on that computer. If you want to listen to music stored on a computer in another room, you can use the network to access the music files. Sharing a Printer

If you have a printer connected to your computer, you can share the printer with other  computers on the network. Then instead of buying a printer for every computer, all the computers computers can print across the network to the printer. Suppose you want to print a document on a color laser printer that is connected to another computer in the office. Instead of copying your file to a disk, going to the other computer, and interrupting the person using that computer, you can print directly over the network. Sharing an Internet Connection

If you already have access to the Internet from one computer on your network, you can share that Internet connection with other computers on the network. Then all the computers on your  network can browse the Web at the same time, using this single Internet connection. Networking Components

To network computers together, you need to install networking hardware and software. Every network includes these three components: The computers that are connected together. Computers and similar devices are called nodes when connected to a network. The networking hardware that connects the computers together, including hardware installed in your computer, network cables, and devices that connect all the cables together.  Networking  Networking software that runs on each computer and enables it to communicate communicate with other computers on the network.

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Networking Hardware

Here is the networking hardware you need to set up a small network: Network adapter cards: expans expansio ion n cards cards that that provi provide de the phy physic sical al conne connecti ction on betw between een each each comput computer er and the the network. The card installs into a slot on your computer, just like a sound card or modem card. Some Some newer newer comput computers ers have have a networ network k adapt adapter er alrea already dy built built into into the syst system em.. Lapt Laptop op computers often use a card that slides into a PC card slot.

special al,, unshi unshiel elded ded twist twisteded-pa pair ir (UTP (UTP)) cabl cables es used used to conne connect ct each each Network Network cables: cables: speci computer to the hub. The cable you need is Category 5 UTP cable with a square plastic RJ-45 connector on each end.

All the networking hardware described here is known as Ethernet. Ethernet is the industrywide standard for computer networks. Standard Ethernet networks transmit data at 10 million  bits per second (Mbps). A newer Ethernet standard, called Fast Ethernet, transmits data at 100 Mbps. Computer networks often contain a mixture of 10 Mbps and 100 Mbps devices.

Types of Networks The type of network described in this book is a simple local network, often called a local area network or LAN. A LAN connects computers together at one location. Small Peer-to-Peer Networks You can build a simple, small network without using the complex and expensive equipment used used in large large netwo networks rks.. On such such a netwo network, rk, often often calle called d apeer apeer-to -to-p -peer eer netwo network, rk, each each computer can communicate with any other computer on the network.

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You You can can connec connectt comput computer erss toget together her using using networ network k cable cabless and a hub hub,, or use wirel wireles esss technology to network the computers. The focus of this book is on building a simple peer-to-peer network. Peer-to-peer networks are easy to install and maintain, and they give you many of the advantages of a large network. A peer-to-peer network is the obvious choice for a network in a home or small office. You can set up this network yourself, yourself, without buying an expensive server, and without paying for  the services of a network administrator to install and manage the network. Peer-to-peer networking has gained recent popularity on the Internet. Computers connected to the Internet communicate directly with each other and share files. The software to set up a local peer-to-peer network has been included in Windows since the release of Windows 95. People have been building simple peer-to-peer networks since that time, using the software  built into Windows. clients on the network access the servers to log on, access files, and print documents. The servers may be running networking software from Novell or Microsoft, or they may be running the UNIX or Linux"!" operating systems.

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Large networks are usually constructed by connecting several small networks together with special networking equipment equipment that controls communication communication between the smaller segments of  subnetworks or Subnets A ring network is a network topology in which each node connects to exactly two other  nodes, forming a single continuous pathway for signals through each node - a ring. Data travels from node to node, with each node along the way handling every packet. Advantages

Very orderly network where every device has access to the token and the opportunity to transmit Performs better than a star topology under heavy network load Can create much larger network using Token Ring Does not require network server to manage the connectivity between the computers Disadvantages

One malfunctioning workstation or bad port in the MAU can create problems for the entire network  Moves, adds and changes of devices can affect the network   Network adapter cards and MAU's are much more expensive than Ethernet cards and hubs Much slower than an Ethernet network under normal load

REMOTE CONNECTION

Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft, which concerns providing a user with a graphical interface to another computer. Microsoft currently refers to their official RDP server software as Remote Desktop Services, formerly "Terminal Services". Their official client software is currently referred to as Remote Desktop Connection, formerly "Terminal Services Client".

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UNIT-6 COMPUTER VIRUS AND MAINTEANCE

A computer virus is a computer computer program that can copy itself and infect a computer. The term "virus" is also commonly but erroneously used to refer to other types of malware, including  but not limited to adware and spyware programs that do not have the reproductive ability. A true virus can spread from one computer computer to another (in some form of executable executable code) when its host is taken to the target computer; for instance because a user sent it over a network or  the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or USB drive. Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another computer. As stated above, the term "computer virus" is sometimes used as a catch-all phrase to include all types of malware, even those that do not have the reproductive ability. Malware includes computer computer viruses, computer worms, Trojan horses, most rootkits, spyware, dishonest adware and other malicious and unwanted software, including true viruses. Viruses are sometimes confused with worms and Trojan horses, which are technically different. A worm can exploit security vulnerabilities to spread itself automatically to other computers through networks, while a Trojan horse is a program that appears harmless but hides malicious functions. Worms and Trojan horses, like viruses, may harm a computer computer system's system's data or performance. Some viruses and other malware have symptoms noticeable to the computer user, but many are surreptitious or simply do nothing to call attention to themselves. Some viruses do nothing beyond reproducing themselves The first academic work on the theory of computer viruses (although the term "computer  virus" was not invented at that time) was done by John von Neumann in 1949 who held lectures at the University of Illinois about the "Theory and Organization of Complicated Auto Automa mata ta". ". Th Thee work work of von von Neum Neuman ann n was was late laterr publ publis ishe hed d as the the "The "Theor ory y of self self-reproducing automata".[5] In his essay von Neumann postulated that a computer program could reproduce In order to avoid detection by users, some viruses employ different kinds of deception. Some old viruses, especially on the MS-DOS platform, make sure that the "last modified" date of a host file stays the same when the file is infected by the virus. This approach does not fool anti-virus software, however, especially those which maintain and date Cyclic redundancy checks on file changes. Some viruses can infect files without increasing their sizes or damaging the files. They accomplish this by overwriting unused areas of executable files. These are called cavity viruses. For example, the CIH virus, or Chernobyl Virus, infects Portable Executable files. Because those files have many empty gaps, the virus, which was 1 KB in length, did not add to the size of the file. Some viruses try to avoid detection by killing the tasks associated with antivirus software  before it can detect them. As computers and operating systems grow larger and more complex, old hiding techniques need to be updated or replaced. Defending Defending a computer computer against viruses may demand that a file system migrate towards detailed and explicit permission for every kind of file access. 52

Anti-virus software and other preventive measures

Many users install anti-virus software that can detect and eliminate known viruses after the computer downloads or runs the executable. There are two common methods that an antivirus software application uses to detect viruses. The first, and by far the most common meth method od of virus virus detec detecti tion on is using using a list list of virus virus signa signatu ture re defini definiti tions ons.. Th This is works works by examining the content of the computer's memory (its RAM, and boot sectors) and the files stored on fixed or removable drives (hard drives, floppy drives), and comparing those files against a database of known virus "signatures". The disadvantage disadvantage of this detection method is that users are only protected protected from viruses that pre-date their last virus definition update. The second method is to use a heuristic algorithm to find viruses based on common behaviors. This method has the ability to detect novel viruses that anti-virus security firms have yet to create a signature for. Virus removal

One possibility on Windows Me, Windows XP, Windows Vista and Windows 7 is a tool known as System Restore, which restores the registry and critical system files to a previous checkpoint. Often a virus will cause a system to hang, and a subsequent hard reboot will render a system restore point from the same day corrupt. Restore points from previous days should work provided the virus is not designed to corrupt the restore files or also exists in   previou previouss restore restore points.[ points.[33] 33] Some Some viruses, viruses, however however,, disable disable System System Restore Restore and other  other  important tools such as Task Manager and Command Prompt. An example of a virus that does does this this is CiaD CiaDoor oor.. Howe However ver,, many many such such viruse virusess can can be remo removed ved by reboot rebooting ing the the computer, entering Windows safe mode, and then using system tools. Administrators have the option to disable such tools from limited users for various reasons (for example, to reduce potential damage from and the spread of viruses). A virus can modify the registry to do the same even if the Administrator Administrator is controlling the computer; it blocks all users including the administrator from accessing the tools. The message "Task Manager has  been disabled by your administrator" may be displayed, even to the administrator  Operating system reinstallation

Reinstalling the operating system is another approach to virus removal. It involves either  reformatting the computer's hard drive and installing the OS and all programs from original media, or restoring the entire partition with a clean backup image. User data can be restored  by booting from a Live CD, or putting the hard drive into another computer and booting from its operating system with great care not to infect the second computer by executing any infected programs on the original drive; and once the system has been restored precautions must be taken to avoid reinfection from a restored executable file. These methods are simple to do, may be faster than disinfecting a computer, and are guaranteed guaranteed to remove any malware. malware. If the operating system and programs must be reinstalled from scratch, the time and effort to reinstall, reconfigure, and restore user preferences must  be taken into account. Restoring from an image is much faster, totally safe, and restores the exact configuration to the state it was in when the image was made, with no further trouble.

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