Basic Structure of Computers PDF

Topic 01A Basic Structure of Computers  Objectives Describe basic computer components and operation Explain the fundamentals of network communication Hands on LINUX Operating System Understand Client/server Application Describe basic cloud Computing services Guide to Networkin...

Topic 01A Basic Structure of Computers  Objectives Describe basic computer components and operation Explain the fundamentals of network communication Hands on LINUX Operating System Understand Client/server Application Describe basic cloud Computing services Guide to Networking Essentials, 7th Edition 2  Objectives Describe basic computer components and operation Explain the fundamentals of network communication Hands on LINUX Operating System Understand Client/server Application Describe basic cloud Computing services Guide to Networking Essentials, 7th Edition 3  PHP ==> scripting language command line processor Apache ==> Web Server Sample Web Application TCP/IP LINUX Hardware 4 © Cengage Learning 2016  An Overview of Computer Concepts Most devices encountered when working with a network involve a computer Most obvious devices are workstations (PCs and laptops) and network servers running operating systems such as: Windows, Linux, UNIX, and Mac OS Also includes routers and switches Specialized computers used to move data from computer to computer and network to network You will learn more about them in later chapters Guide to Networking Essentials, 7th Edition 5  Basic Functions of a Computer A computer’s functions can be broken down into three basic tasks: Input: A user types the letter ‘A’ on the keyboard, which results in sending a code representing the letter ‘A’ to the computer Processing: The computer’s CPU determines what letter was typed by looking up the keyboard code in a table Output: The CPU sends instructions to the graphics cards to display the letter ‘A’, which is then sent to the computer monitor Guide to Networking Essentials, 7th Edition 6  Components of a Computer Guide to Networking Essentials, 7th Edition 7  Input Components Common user controlled devices such as keyboards, microphones, Webcams, and scanners External interfaces, such as serial, FireWire, and USB ports can also be used to get input from external devices. Storage devices such as hard disks and CDs/DVDs Guide to Networking Essentials, 7th Edition 8 Guide to Networking Essentials, 7th Edition 9  Processing Components CPU: a computer’s main processing component Executes instructions from computer programs, such as word processors and from the computer’s operating system Current CPUs are composed of two or more processors called cores A multicore CPU is like a person with two brains Multicore CPUs enable computers to carry out multiple instructions simultaneously Results in better overall performance Guide to Networking Essentials, 7th Edition 10  Output Components Most obvious are monitors and printers Also include storage devices, network cards, and speakers External interfaces For example, a disk drive connected to a USB port allows reading files from the disk (input) and writing files to the disk (output) Guide to Networking Essentials, 7th Edition 11  Storage Components The more storage a computer has, the better the performance Most storage components are both input and output devices Most people think of storage as disk drives, CD/DVD drives, and USB flash drives. Two main categories of storage Short-term storage Long-term storage Guide to Networking Essentials, 7th Edition 12  Comparing temporary and permanent storage Guide to Networking Essentials, 7th Edition 13  RAM: Short-Term Storage Random Access Memory (RAM) – when power to the computer is turned off, RAM’s contents are gone Short-term storage (volatile) The amount of RAM in a computer is crucial to the computer’s capability to operate efficiently RAM is also referred to as “working storage” If there’s not enough RAM to run a program, the computer will use the disk drive to supplement (virtual memory) Guide to Networking Essentials, 7th Edition 14  Virtual Memory Part of disk storage can be set as virtual memory CPU can only access data/code in RAM Less used data/code are placed in virtual memory Data/code needed by CPU are moved to RAM Guide to Networking Essentials, 7th Edition 15  Long-Term Storage Maintains its data even when there’s no power (non-volatile) Examples: Hard disks CDs/DVDs USB flash drives Used to store document and multimedia files As well as application and OS files Amount of storage a computer needs depends on the type and quantity of files to be stored Guide to Networking Essentials, 7th Edition 16  Personal Computer Hardware Four major PC components: Motherboard Hard drive RAM BIOS/CMOS Guide to Networking Essentials, 7th Edition 17  The Motherboard and Its Components Guide to Networking Essentials, 7th Edition 18  The Motherboard and Its Components Guide to Networking Essentials, 7th Edition 19  Computer Bus Fundamentals Bus: a collection of wires carrying signals (data, address or control) from one place to another on the computer All data that goes into or comes out of a computer goes through the motherboard There are buses between: CPU and RAM CPU and disk drives CPU and expansion slots Guide to Networking Essentials, 7th Edition 20  Computer Bus Fundamentals Data Bus Both Read/Write Used to carry data signals from main memory (Ram) to CPU and vice versa or from main memory (Ram) to input/output (I/O) devices vice versa Address Bus Used to carry address signals, example a memory location or port/interface where an input or output device is attached Control Bus Used to carry control signals, example read or write, from CPU to memory or port/interface Guide to Networking Essentials, 7th Edition 21 Guide to Networking Essentials, 7th Edition 22 Guide to Networking Essentials, 7th Edition 23 Difference between Address bus and data bus The data bus carries the data to be stored, while address bus carries the location to where it should be stored.  I/O Polling and Interrupt We have many external devices attached to the CPU like a mouse, keyboard, scanner, printer, etc. These devices also need CPU attention. Suppose, a CPU is busy in displaying a PDF and Polling and Interrupt let CPU stop you click the window media player icon on the what it is currently doing and desktop. Though the CPU does not have any respond to the more important task. Polling and Interrupt are different idea when an event like this would occur, from each other in many aspects. But but it has to respond to such inputs from the basic point that distinguishes the I/O devices. Interrupt and Polling are the Polling and Interrupt is that in two ways to handle the events generated by polling CPU keeps on checking I/O the devices that can happen at any moment devices at regular interval whether it while CPU is busy in executing another process. needs CPU service whereas, in interrupt, the I/O device interrupts the CPU and tell CPU that it need CPU service. https://techdifferences.com/difference-between-interrupt-and-polling-in-os.html  Hard Drive Fundamentals Hard drive: primary long-term storage component on your computer Consist of magnetic disks called “platters” that store data in the form of magnetic pulses Stores the documents you use as well as the applications that open those documents Stores the OS your computer loads when it boots Guide to Networking Essentials, 7th Edition 26  Hard Drive Fundamentals Guide to Networking Essentials, 7th Edition 27  Solid State Drives SSDs are used in place of hard drives Due to speed and reliability SSDs use flash memory No moving parts and has faster access times More expensive than hard drives Most often found in mobile devices Also found in high-performance desktops and servers Guide to Networking Essentials, 7th Edition 28  RAM Fundamentals RAM is the main short-term storage component on a computer RAM has no moving parts so accessing data in RAM is much faster than accessing data on a hard drive In general, the more RAM your system has the faster it will run Static RAM - expensive but fast Dynamic RAM - cheap Guide to Networking Essentials, 7th Edition 29  BIOS/CMOS Fundamentals BIOS: basic input/output system Set of instructions located in a chip on the motherboard Tells the CPU to perform certain tasks when power is first applied to the computer One of those instructions is to perform a power-on self test (POST)=> Check all the components while powering on When a computer boots, the BIOS program offers a chance to run the Setup utility in order to configure hardware components This configuration is stored in a type of memory called complementary metal oxide semiconductor (CMOS) ROM ==> used to to start up a computer (CONTAINS BIOS) EPROM EEPROM Guide to Networking Essentials, 7th Edition 30  Computer Boot Procedure 1. Power is applied to the motherboard 2. The CPU starts 3. The CPU carries out the BIOS startup routines, including the POST(Power-on self-test) 1. Boot devices, as specified in the BIOS configuration, are searched for an OS 2. The OS is loaded into RAM 3. OS services are started Power => Motherboard => CPU => BIOS => POST [process] => search OS => OS => RAM => PC started Guide to Networking Essentials, 7th Edition 31  The Fundamentals of Network Communication A computer network consists of two or more computers connected by some kind of transmission medium Such as a cable or air waves In order to access the Internet, a computer has to be able to connect to a network The next few slides will cover what is required to turn a standalone computer into a networked computer UTP => Unshielded Twisted Pair UEFI => Unified Extensible Firmware Interface Guide to Networking Essentials, 7th Edition 32  NIC Basics Attaching a computer to a network requires a network interface card (NIC) to create and mediate the connection between a computer and the networking medium It contains MAC address(Media Access Control Address) Unique identifier assigned to NIC Networking medium might be copper wire, fiber-optic cable, or airwaves MAC is a Unique Identifier. Guide to Networking Essentials, 7th Edition 33  Wireless NICs Wireless NICs must be chosen according to type of wireless AP being used Typical are Wireless-n, 802.11ac or 802.11 a/b/g/n The letter a,b,g, n, and ac refer to the wireless networking standard the device supports Wireless NICs connect to network using service set identifier (SSID) SSID is the name assigned to the wireless network You may also need to enter a security key or a username and password, depending on the network’s security configuration Guide to Networking Essentials, 7th Edition 34 Types of computers 1) Embedded computers 2) Personal computers 3) Servers and Enterprise systems Use UPS - Uninterrupted Power Supply 4) Supercomputers and Grid computers 5) “Cloud” computing Microsoft - Azure The “heart” of the computer is the CPU or Central Processing Unit, also called the Processor Online Video: https://youtu.be/yRmPTbGBqVI