Introduction To Computer Systems PDF

1 2.1 INTRODUCTION TO COMPUTER SYSTEMS; COMPUTER SYSTEMS ARCHITECTURE Lecturer: Information and Communications Technologies Elvira Aitmukhanbetova [email protected]  Copyright Notice 2 ¨ This presentation is presented as is. Most of the...

1 2.1 INTRODUCTION TO COMPUTER SYSTEMS; COMPUTER SYSTEMS ARCHITECTURE Lecturer: Information and Communications Technologies Elvira Aitmukhanbetova [email protected]  Copyright Notice 2 ¨ This presentation is presented as is. Most of the information is from: ¤ The Architecture of Computer Hardware, Systems Software & Networking: An Information Technology Approach n 5th Edition, Irv Englander; John Wiley and Sons ©2013 ¨ Other information was collected from various websites or sources across the web. ¤ This presentation uses Creative Commons Attribution 4.0 International (CC BY 4.0). © 2020 BilimEdtech 3 2.1: Computers and Systems 2.1: Computers and Systems 2.2: System Concepts and Architecture 2.3: IT System Architecture  Learning Objectives 4 ¨ Understand the Input-Process-Output Model (IPO) ¨ List the components of a computer system ¨ Explain the purpose of each component ¨ Describe virtualization ¨ Explain the purpose of standards  Modern Computing 5 ¨ Personal computing is ubiquitous ¤ It is everywhere and anywhere ¤ No longer limited to a traditional ‘computer’ ¤ Greater variety of computing platforms exist now ¨ Computing is widespread ¤ Embedded in many other types of devices such as appliances and automobiles ¤ Users no longer have to understand the details of how they work to operate the device  Why Study Computer System Architecture? 6 ¨ Understand system capabilities, strengths, and limitations ¨ Make better informed decisions ¨ Improve communications with information technology professionals  Web Browser Application Example 7  Web Browser Application IPO 8  Input-Process-Output Model (IPO) 9 ¨ Input ¤ keyboard, mouse, scanner ¨ Process ¤ CPU executes the computer program ¨ Output ¤ monitor, printer, fax machine ¨ Storage ¤ hard drive, optical media, diskettes, magnetic tape  Computer System Components 10 ¨ Hardware ¨ Software ¨ Data ¨ Communication  Computer System Components 11 ¨ Hardware ¤ Processes data by executing instructions ¤ Provides input and output ¤ Controls input, output, and storage components ¨ Software ¤ Applications and system software ¤ Instructions tell hardware exactly what tasks to perform and in what order  Computer System Components 12 ¨ Data ¤ Fundamental representation of facts and observations ¨ Communications ¤ Sharing data and processing among different systems  Hardware Component 13 ¨ Input/output devices ¨ Memory ¨ Storage Devices ¤ Short-term storage for CPU calculations ¨ CPU – Central Processing Unit ¤ ALU: arithmetic/logic unit ¤ CU: control unit ¤ Interface unit  Hardware Components of a PC 14  CPU: Central Processing Unit 15 ¨ ALU: arithmetic/logic unit ¤ Performs arithmetic and Boolean logical calculations ¨ CU: control unit ¤ Controls processing of instructions ¤ Controls movement of data within the CPU ¨ Interface unit ¤ Moves instructions and data between the CPU and other hardware components ¤ Bus: bundle of wires that carry signals and power between different components  Memory 16 ¨ Also known as primary storage, working storage, and RAM (random access memory) ¨ Consists of bits, each of which hold a value of either 0 or 1 (8 bits = 1 byte) ¨ Holds both instructions and data of a computer program (stored program concept)  Software Component 17 ¨ Applications ¨ Operating System ¤ API: application program interface ¤ File management ¤ I/O ¤ Kernel n Memory management n Resource scheduling n Program communication n Security ¤ Network Module  Communication Component (1 of 2) 18 ¨ Hardware ¤ Communication channels n Physical connections between computer systems n Examples: wire cable, phone lines, fiber optic cable, infrared light, radio waves ¤ Interface hardware n Handles communication between the computer and the communication channel n Modem or network interface card (NIC)  Communication Component (2 of 2) 19 ¨ Software ¤ Establish connections ¤ Control flow of data ¤ Directs data to the proper applications for use  Computer Systems 20 ¨ All computer systems, no matter how complex, consists of the following: ¤ At least one CPU ¤ Memory to hold programs and data ¤ I/O devices ¤ Long-term storage  Computer Systems Examples 21  Virtualization 22 ¨ Virtual ¤ not physically existing as such but made by software to appear to do so ¤ Created, simulated, or carried on by means of a computer or computer network ¨ Virtual computer systems examples ¤ memory, networks, and operating systems  Virtual Private Network (VPN) 23  Real vs. Virtual Keyboard 24  Standards 25 ¨ Created to ensure universal compatibility of data formats and protocols ¨ Examples: ¤ Computer languages: Java, SQL, C, JavaScript ¤ Display standards: Postscript, MPEG-2, JPEG, PNG ¤ Character set standards: ASCII, Unicode, EBCDIC ¤ Multimedia standards: MPEG-2, MPEG-4, MP3, DVD-ROM  QWERTY Keyboard Layout 26  Protocols 27 ¨ Common ground rules of communication between computers, I/O devices, and many software programs ¨ Examples ¤ HTTP: between Web servers and Web browsers ¤ TCP/IP: between computers on the Internet and local area networks ¤ SATA: between storage devices and computers ¤ XML,RSS, SIP: new protocols developed to meet new demands  TCP and UDP: Internet Protocols 28 ¨ TCP: Transmission Control Protocol ¤ Ensures delivery of data ¤ If data is corrupt or not delivered, the data is resent ¨ UDP: User Datagram Protocol ¤ Data is sent with no confirmation of delivery ¤ If data is corrupted, the receiver discards the data  Summary 29 ¨ Input-process-output (IPO) model is a fundamental design of computer system architecture ¨ A computer is a self-contained system composed of hardware, software, and data that communicates ¤ CPU, memory, input/output devices, and storage ¨ Virtualization is a software-based computer system ¨ Protocols are standards that define communication rules 30 2.2: System Concepts and Architecture 2.1: Computers and Systems 2.2: System Concepts and Architecture 2.3: IT System Architecture  Learning Objectives 31 ¨ Describe a system ¨ List the components of a system ¨ Describe each component in detail ¨ Explain system decomposition ¨ Discuss the difference between system architecture and abstraction  What is a system? 32 ¨ What do the following systems have in common? ¤ Plumbing system ¤ Solar system ¤ Home network system ¤ Inventory control system  What is a system? 33 ¨ What do the following systems have in common? ¨ Each is built up from a set of components that are linked together to form what we think of as a single unit.  Plumbing System 34  Solar System 35  Home Network System 36  Inventory Control System 37  Definition of a System 38 ¨ “A system is a collection of components linked together and organized in such a way as to be recognizable as a single unit” ¨ Linked components of a system also define a boundary for the system ¨ The environment is anything outside of the system  General Representation of a System 39  Definition of an Interface 40 ¨ In computing, an interface is a shared boundary across which two or more separate components of a computer system exchange information.  Different Interfaces 41  A Simple E-Business System 42  System Decomposition 43 ¨ Components ¤ May be irreducible or ¤ May be subsystems ¨ Decomposition ¤ The division of a system into its components and linkages ¤ Hierarchical  Hierarchy of the Internet 44  System Architecture 45 ¨ “The fundamental properties and the patterns of relationships, connections, constraints, and linkages among the components and between the system and its environment are known collectively as the architecture of the system”  Abstractions of Systems 46 ¨ Abstractions are not the real system ¤ Representation ¤ Organization ¤ Simplification  Abstractions of Systems 47 ¨ How are the following two abstractions of a business system different from one another? ¨ How are these abstractions different from the real business system?  Business Organization Chart 48  Business Application Architecture 49  Summary 50 ¨ A system is a set of components that are linked together to form what we think of as a single unit. ¤ Components may be a single unit or a subsystem ¤ The links could be permanent, temporary, tangible, intangible ¤ The environment interacts with the system through interfaces ¨ System architecture is the fundamental properties and the patterns of relationships and connections among the components and between the system and its environment. ¨ System abstraction is a representation of the architecture 51 2.3: IT System Architecture 2.1: Computers and Systems 2.2 System Concepts and Architecture 2.3: IT System Architecture  Learning Objectives 52 ¨ Explain the purpose IT system architectures ¨ List three types of distributed processing systems ¨ Describe client-server, cloud, and peer-to-peer computing ¨ Gives examples of client-server architecture ¨ Compare the three types of cloud-computer services  Application Architecture 53 ¨ Characterized by the flow and processing of data ¤ Within an organization ¤ Between organizations ¤ Between an organization and its environment  IT System Architectures 54 ¨ System concepts are applicable to IT systems ¨ IT systems ¤ Complex ¤ Multi-layered (with numerous subsystems)  Distributed processing systems 55 ¨ Today’s organizations rely on communication and access to data  Distributed Processing Systems 56 ¨ Client-Server Computing ¤ Two-tier architecture ¤ Three-tier architecture ¤ N-tier architecture ¨ Cloud Computing ¨ Peer-to-Peer Computing  Client-Server Computing 57 ¨ A program on a client computer requests services from a server computer ¨ Examples of services: ¤ Email, file, print, directory, web, database, application, remote access services  Basic Two-tier Client-Server Architecture 58 ¨ Two-tier architecture simply means that there are two computers involved in the service.  Web browser-Web server Model 59  Clients and Servers on a Network 60 ¨ Dedicated server ¤ Running a single service ¨ Shared server ¤ Running multiple services ¤ S2 is a shared server  Advantages of Client-Server Architecture 61 ¨ Centralization of services permits ¤ easier administration of services by IT professionals ¤ easier availability and location by users ¤ consistency of resources, such as files and data, can be managed and assured  Multi-tier Architectures 62 ¨ Two-tier architecture ¤ Two computers are involved in a service ¨ Three-tier architecture ¤ Three computers are involved in a service ¨ N-tier architecture ¤ N number of computers involved in a service  Multi-tier Architectures: Two-tier 63 ¨ Two-tier architecture ¤ Two computers are involved in a service ¤ Web browser and Web server model used in intranets and on the Internet  Multi-tier Architectures: Three-tier 64 ¨ Three-tier architecture ¤ Three computers are involved in a service ¤ Example: a client computer, a web server, and a database server  Three-tier Web-based Email Architecture 65  Multi-tier Architectures: N-tier 66 ¨ N-tier architecture can: ¤ Result in better overall control ¤ Simplify system upgrades ¤ Minimize scalability issues ¨ Tiers can be added or removed to meet demand  Cloud Computing (1 of 2) 67 ¨ Cloud computing includes: ¤ Server ¤ Virtual desktops ¤ Software platforms ¤ Applications ¤ Storage  Cloud Computing (2 of 2) 68 ¨ Software as a service (SaaS) ¨ Platform as a service (PaaS) ¨ Infrastructure as a service (IaaS)  Software as a service (SaaS) 69 ¨ Software as a service (SaaS) ¤ applications that run on a server ¤ data processing may be divided on server and client  Platform as a Service (PaaS) 70 ¨ Platform as a service (PaaS) ¤ used to host an application or service ¤ Virtually hosts websites, databases, or operating systems  Infrastructure as a Service (IaaS) 71 ¨ Infrastructure as a service (IaaS): Virtualized hardware systems ¨ Infrastructure is composed of resources that support the flow, storage, processing, and analysis of data.  Infrastructure as a Service (IaaS) 72 ¨ Infrastructure as a service (IaaS) ¤ cloud-based hardware emulation of virtual machines and networking  Peer-to-Peer Computing 73 ¨ Computers on a network are treated as equals ¨ Each computer can share resources with the other computers on the network  Peer-to-Peer Computing: Disadvantages 74 ¨ Disadvantages ¤ Difficult to locate services ¤ Difficult to synchronize versions of files or software ¤ Difficult to secure network from unauthorized access and from viruses  Peer-to-Peer Computing: Advantages 75 ¨ Advantages ¤ Easy to set up, no need for a server ¤ Sharing files between personal computers ¤ If a client goes offline, the files are still available on another  Hybrid Model of Computing 76 ¨ Client-server technology used to locate systems and files ¨ Then systems can participate in peer-to- peer transactions  Summary 77 ¨ Application architecture is characterized by the flow and processing of data ¨ Distributed processing systems are examples of application architecture. DPS Computing models: ¤ Client-server: a client requesting information from a server ¤ Cloud: using virtualized servers and systems on the internet ¤ Peer-to-peer: clients communicate to each other without a server