"Computer Hardware and Networking: A Comprehensive Guide for Technicians", Lecture notes of Computer Networks

Download "Computer Hardware and Networking: A Comprehensive Guide for Technicians" and more Lecture notes Computer Networks in PDF only on Docsity! Computer Hardware Technician Author: Mr. Ali Hassnain (Cyber MSO) Title module week theory practical weeks fundamental of IT module 1 2 4 30 74 4 computer Assembling module 2 50 108 5 software module 3 22 180 5 Networking module 4 28 65 3 Internet module 5 23 120 4 trouble shooting module 6 0 100 3 Computer Hardware Technician Author: Mr. Ali Hassnain (Cyber MSO) What is computer? An electronic machine to which we give input, it process on the given input, and gives us the output. • Input is • Processing • Output is DATA Author: Mr. Ali Hassnain (Cyber MSO) Computer A programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or processes information. Author: Mr. Ali Hassnain (Cyber MSO) What is Data • DATA is Raw facts • Suppose You are given a task for collection of computer prices (for example corei3 with 300GB Harddisk 2GB RAM ) • Visit market and collect prices (It is raw fact) Author: Mr. Ali Hassnain (Cyber MSO) Characteristics of Information – accurate, – complete, – economical, – flexible, – reliable, – relevant, – simple, – timely, – verifiable, – accessible, – secure Author: Mr. Ali Hassnain (Cyber MSO) Analog • Analog is a continuous waveform, with examples such as (naturally occurring) music and voice Author: Mr. Ali Hassnain (Cyber MSO) Digital • Digital is a discrete or non-continuous waveform Author: Mr. Ali Hassnain (Cyber MSO) Electrical and Electronics Author: Mr. Ali Hassnain (Cyber MSO) Voltage or Potential Difference • The applied potential difference (in volts) of a voltage source in an electric circuit is the “pressure” to set the system in motion and “cause” the flow of charge or current through the electrical system. Author: Mr. Ali Hassnain (Cyber MSO) Current • The free electron is the charge carrier in a copper wire or any other solid conductor of electricity • With no external forces applied, the net flow of charge in a conductor in any one direction is zero • Basic electric circuit Author: Mr. Ali Hassnain (Cyber MSO) Semiconductors • Semiconductors are a specific group of elements that exhibit characteristics between those of insulators and conductors • Semiconductor materials typically have four electrons in the outermost valence ring • Semiconductors are further characterized as being photoconductive and having a negative temperature coefficient – Photoconductivity: Photons from incident light can increase the carrier density in the material and thereby the charge flow level – Negative temperature coefficient: Resistance will decrease with an increase in temperature (opposite to that of most conductors) Author: Mr. Ali Hassnain (Cyber MSO) DIODE Author: Mr. Ali Hassnain (Cyber MSO) Diode • Diodes are made of semiconductors (usually silicon) • Essentially a stack of p-doped and n-doped silicon to form a p-n junction – doping means deliberate impurities that contribute extra electrons (n- doped) or “holes” for electrons (p-doped) p-type n-type Author: Mr. Ali Hassnain (Cyber MSO) DIODE Convert AC into DC AC source load input voltage Diode only conducts when input voltage is positive output voltage Author: Mr. Ali Hassnain (Cyber MSO) Doing Better: Full-wave Diode Bridge • The diode in the rectifying circuit simply prevented the negative swing of voltage from conducting – but this wastes half the available cycle – also very irregular (bumpy): far from a “good” DC source • By using four diodes, you can recover the negative swing: A C B D AC source load input voltage voltage seen by load B & C conduct A & D conduct Author: Mr. Ali Hassnain (Cyber MSO) Electricity uses up a little energy pushing its way through the diode. This means that there is a small voltage across a conducting diode, it is called the forward voltage drop and is about 0.7V for all normal diodes DIODE Forward Voltage Drop Author: Mr. Ali Hassnain (Cyber MSO) Voltage Regulator • Can trim down voltage to precise, rock-steady value Author: Mr. Ali Hassnain (Cyber MSO) Transistors (controlling current) • Transistors have made our modern world possible • Sort-of like diodes end-to-end (npn and pnp junctions – but the sandwiched junction is very thin, and this is important • A small current on the “base” can control a large current flowing from “collector” to “emitter” • Can be used as an amplifier – make a weak signal stronger • Or used as a switch – pedal-to-the-metal saturation regime • Both are incredibly useful Author: Mr. Ali Hassnain (Cyber MSO) The Bipolar Junction Transistor The transistor is a versatile device usually configured to perform as a switch or as an amplifier. The bipolar junction transistor (BJT) is the most common type and has three leads: Base Collector Emitter PNP Transistor Base Collector Emitter NPN Transistor In a transistor, the flow of current from the collector to the emitter is controlled by the amount of current flowing into the base of the transistor. If no current flows into the base, no current will flow from the collector to the emitter (it acts like an open switch). If current flows into the base, then a proportional amount of current flows from the collector to the emitter (somewhat like a closed switch). 1 2 3 1 3 2 Author: Mr. Ali Hassnain (Cyber MSO) Resistance and Current • If the resistance in a circuit increases, the current will decrease. • If the resistance in a circuit decreases, the current will increase. • This is an inversely proportional relationship. Resistance and current Author: Mr. Ali Hassnain (Cyber MSO) Ohm’s Law Examples… • If you want to find Voltage : V = IR If I= 2 A and R = 5 Ohms Then, V= (2A)(5Ω) = 10 V Ohm’s Law Author: Mr. Ali Hassnain (Cyber MSO) Transformer power supply is linear. Nowadays most of them are of SMPS type. What is it? The units in which the energy flow is controlled with semiconductors that are continuously switching on and off with high frequency are referred to as switch mode power supplies. Linear vs SMPS (SWITCH MODE POWER SUPPLY) Author: Mr. Ali Hassnain (Cyber MSO) Basic Logic Gates Author: Mr. Ali Hassnain (Cyber MSO) AND Gate AND X Y Z Z = X & Y X Y Z 0 0 0 0 1 0 1 0 0 1 1 1 Author: Mr. Ali Hassnain (Cyber MSO) OR Gate OR X Y Z Z = X | Y X Y Z 0 0 0 0 1 1 1 0 1 1 1 1 Author: Mr. Ali Hassnain (Cyber MSO) NOR Gate NOR X Y Z X Y Z 0 0 1 0 1 0 1 0 0 1 1 0 Z = ~(X | Y) nor(Z,X,Y) Author: Mr. Ali Hassnain (Cyber MSO) Exclusive-OR Gate X Y Z XOR X Y Z 0 0 0 0 1 1 1 0 1 1 1 0 Z = X ^ Y xor(Z,X,Y) Author: Mr. Ali Hassnain (Cyber MSO) Exclusive-NOR Gate X Y Z XNOR X Y Z 0 0 1 0 1 0 1 0 0 1 1 1 Z = ~(X ^ Y) Z = X ~^ Y xnor(Z,X,Y) Author: Mr. Ali Hassnain (Cyber MSO) Integrated Circuits Integrated circuit (also called a chip) A piece of silicon on which multiple gates have been embedded Silicon pieces are mounted on a plastic or ceramic package with pins along the edges that can be soldered onto circuit boards or inserted into appropriate sockets Author: Mr. Ali Hassnain (Cyber MSO) Integrated Circuits Integrated circuits (IC) are classified by the number of gates contained in them Author: Mr. Ali Hassnain (Cyber MSO) CPU Chips The most important integrated circuit in any computer is the Central Processing Unit, or CPU Each CPU chip has a large number of pins through which essentially all communication in a computer system occurs Author: Mr. Ali Hassnain (Cyber MSO) First Generation Computers 1951-1959 • Characterized by vacuum tubes which burned out very rapidly. • The first generation of computers used machine language or 0s and 1s. • This generation also used magnetic tape. Author: Mr. Ali Hassnain (Cyber MSO) UNIVAC - 1951 • first fully electronic digital computer built in the U.S. • Created at the University of Pennsylvania • ENIAC weighed 30 tons • contained 18,000 vacuum tubes • Cost a paltry $487,000 Author: Mr. Ali Hassnain (Cyber MSO) DISADVANTAGES: • They generate more heat causing many problems in temperature regulation and climate control. • Tubes were subject to frequent burn-out. Author: Mr. Ali Hassnain (Cyber MSO) Fourth Generation 1975-Today • These computers use microprocessor chips. • Object-Oriented Programming (OOP) Languages such as Visual Basic, and JAVA are characteristic of this computer generation. Author: Mr. Ali Hassnain (Cyber MSO) FOURTH GENERATION, • MICROPROCESSOR – is a silicon chip that contains the CPU – part of the computer where all processing takes place. 4004 chip – was the first microprocessor introduced by Intel Corporation. Author: Mr. Ali Hassnain (Cyber MSO) IBM PC - 1981 • IBM-Intel-Microsoft joint venture • First wide-selling personal computer used in business • 8088 Microchip - 29,000 transistors – 4.77 Mhz processing speed • 256 K RAM (Random Access Memory) standard • One or two floppy disk drives Author: Mr. Ali Hassnain (Cyber MSO) A Fifth Generation? AI Artificial Intelligence (sensors) Author: Mr. Ali Hassnain (Cyber MSO) • Artificial intelligence – Expert systems, simulation of human sensory capabilities, neural networks, intelligent agents, robots and robotics Author: Mr. Ali Hassnain (Cyber MSO) • Virtual reality – Combines computer graphics with special hardware to immerse users in an artificial three-dimensional world Author: Mr. Ali Hassnain (Cyber MSO) Processor speed - measured in megahertz (MHz) or Gigahertz (GHz) - the speed of the system clock (clock speed) within the processor and it controls how fast instructions are executed: • 1 MHz - 1 million clock ticks every second • 1 GHz - 1 billion clock ticks every second Latest trend - multi-core processors can have two, three or four processor cores on a single chip. Processor Author: Mr. Ali Hassnain (Cyber MSO) Components of the CPU • Part-1 Control unit • Part-2 Arithmetic logic unit (ALU) • Part-3 Set of registers Author: Mr. Ali Hassnain (Cyber MSO) Control Unit • Like the part of the human brain that control the operation of each part of the body. • Moves data and instructions between main memory and registers Author: Mr. Ali Hassnain (Cyber MSO) CPU Registers • Primary roles – Hold data for currently executing program that is needed quickly or frequently (general-purpose registers) – Store information about currently executing program and about status of CPU (special-purpose registers) Author: Mr. Ali Hassnain (Cyber MSO) CPU Registers • Small, permanent storage locations within the CPU used for a particular purpose • Manipulated directly by the Control Unit • Wired for specific function • Size in bits or bytes (not MB like memory) • Can hold data, an address or an instruction Author: Mr. Ali Hassnain (Cyber MSO) Register • The power and speed of a CPU determined by – the number of registers that a CPU has and – the size of each (number of bits) – For example a 32-bit CPU is one in which each register is 32 bits wide. Therefore, each CPU instruction can manipulate 32 bits of data. Author: Mr. Ali Hassnain (Cyber MSO) Steps of a cycle Author: Mr. Ali Hassnain (Cyber MSO) CPU Example registers ALU input registers ALU A + B A B ALU output register Author: Mr. Ali Hassnain (Cyber MSO) Pre-Fetch • Execution of ALU operations do not access main memory • Can fetch next instruction during execution of current instruction. Fetch Fetch involves accessing main memory Author: Mr. Ali Hassnain (Cyber MSO) Inside ALU • ALU does arithmetic and logical comparisons – AC = accumulator holds results – MQ = memory-quotient holds second portion of long results – MBR = memory buffer register holds data while operation executes Author: Mr. Ali Hassnain (Cyber MSO) Processor Performance • Three methods to improve performance – Multiprocessing • Processor contains more than one ALU – Multiple processors • Installing more than one processor on a motherboard – Multi-core processing • Processor housing contains two or more cores operating at same frequency, independently of each other • Dual core, ?? core, ?? core Author: Mr. Ali Hassnain (Cyber MSO) The CPU is usually protected from Heat by a Heat sink and Fan combination Author: Mr. Ali Hassnain (Cyber MSO) • Primary storage - main computer memory. Data, programs currently in use are held in RAM • Volatile - contents of memory are lost if the computer is turned off • Module - memory IC’s on a circuit board (RAM) IC’s Memory Module Author: Mr. Ali Hassnain (Cyber MSO) Primary Memory • Two basic types of RAM chips exist:  Static RAM (SRAM)  Dynamic RAM (DRAM) Author: Mr. Ali Hassnain (Cyber MSO) Memory • Sequential circuits all depend upon the presence of memory. – A flip-flop can store one bit of information. – A register can store a single “word,” typically 32 or 64 bits. Author: Mr. Ali Hassnain (Cyber MSO) Understanding DRAM • Dynamic random access memory (DRAM) is the most popular type of electronic memory – Special type of semiconductor that stores ones and zeroes using microscopic capacitors and transistors – Single chip that can hold millions of these capacitor/transistor combinations – Limited width of 1, 4, 8+ bits Author: Mr. Ali Hassnain (Cyber MSO) Type of DRAM • Synchronous dynamic RAM (SDRAM) is tied to the system clocks – Synchronized with system clock – Measured in MHz – Comes on DIMM sticks – SO-DIMMs for laptops Author: Mr. Ali Hassnain (Cyber MSO) SDRAM Speeds 133 MHz 100 MHz Clock Speed PC133 PC100 PC66 PC Speed Rating 66 MHz Author: Mr. Ali Hassnain (Cyber MSO)