Untitled Quiz

Introduction to Computer Systems; Computer Systems Architecture

• The presentation is a general overview of computer systems
• The primary resource used is "The Architecture of Computer Hardware, Systems Software & Networking" (5th Edition), by Irv Englander, published in 2013
• Additional information compiled from websites and other sources on the internet
• The presentation uses Creative Commons Attribution 4.0 International license (CC BY 4.0)

Learning Objectives

• Understand the Input-Process-Output (IPO) model
• List the components of a computer system
• Explain the purpose of each component
• Describe virtualization
• Explain the purpose of standards

Modern Computing

• Personal computing is ubiquitous
• Computers are no longer limited to a traditional form factor
• Computing is embedded in a wider range of devices (appliances, automobiles, etc.)
• Users don't often need to understand the internal workings to use them now

Why Study Computer System Architecture?

• Understand capabilities, strengths, and limitations of computer systems
• Enable better decision-making surrounding IT systems
• Improve communication between IT professions and others

Web Browser Application Example

• A diagram illustrating a browser request, communication, and a server response (includes URL, HTTP, and HTML)

Input-Process-Output (IPO) Model

• Input: Keyboard, mouse, scanner
• Process: CPU executes the program
• Output: Monitor, printer, fax machine
• Storage: Hard drive, optical media, diskettes, magnetic tape

Computer System Components

• Hardware: Processes data through instructions, provides input and output
• Software: Applications and system software, instructs hardware on tasks
• Data: Fundamental representation of facts and observations
• Communication: Sharing data and processing between different systems

Hardware Component

• Input/output devices
• Storage devices
• CPU (Central Processing Unit):
  • ALU (arithmetic/logic unit)
  • CU (control unit)
  • Interface unit
• Memory: Short-term storage for CPU calculations

Hardware Components of a PC

• Includes a diagram depicting various components and their connections (CPU, Memory, I/O Interface, Network, Keyboard, Monitor, Mouse, Printer, etc.)

CPU: Central Processing Unit

• ALU: Performs arithmetic and Boolean logical calculations
• CU: Controls the processing of instructions
• Interface unit: Moves instructions and data between the CPU and other hardware components
• Bus: Connects components, handles signals and power

Memory

• Also known as primary storage/working storage/RAM (random access memory)
• Consists of bits (0 or 1), 8 bits = 1 byte
• Holds both instructions and data of a computer program

Software Component

• Applications
• Operating System: (API) application program interface
• File management
• I/O
• Kernel: Memory management , resource scheduling, program communication, security
• Network Module

Communication Component (1 of 2)

• Hardware: Communication channels (physical connections, e.g., wire cable, phone lines, fiber optics)
• Interface hardware: Connects the computer to communication channels (e.g., modems, network interface cards (NICs))

Communication Component (2 of 2)

• Software: Establishing connections, controlling data flow, directing data to the correct applications

Computer Systems

• All computer systems, regardless of complexity, include at least one CPU, memory to hold programs and data, I/O devices, and long-term storage

Computer Systems Examples

• Images of examples, including a smartphone and a small computer box

Virtualization

• Software-created representation of a real system
• Examples include memory, networks, and operating systems

Virtual Private Network (VPN)

• A diagram showing the VPN connection, tunnel, internet, firewall, and perimeter network

Real vs. Virtual Keyboard

• Images of a physical and software keyboard

Standards

• Designed for universal compatibility of data formats and protocols
• Examples include computer languages like Java and C, display standards like JPEG, character set standards like ASCII, and multimedia protocols like DVD-ROM.

QWERTY Keyboard Layout

• Diagram of a QWERTY keyboard layout

Protocols

• Common communication rules between computers, I/O devices, and software
• Examples include HTTP for web servers and browsers, TCP/IP for internet networking, and SATA for storage.

TCP and UDP

• TCP: Transmission Control Protocol
  • Ensures data delivery by re-sending if required
• UDP: User Datagram Protocol
  • Data sent without confirmation of delivery, data loss is acceptable

Summary

• IPO model fundamental for computer system architecture
• Computers are self-contained systems of hardware, software, and data communicating through components (CPU, memory, I/O, storage)
• Virtualization is a software-oriented computer system
• Protocols are communication standards

2.2: System Concepts and Architecture

• Discusses core concepts related to IT systems, their components, and how they interact

Learning Objectives (2.2)

• 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?

• Systems consist of interlinked components working together

Definition of a System

• Describes a system as a series of interlinked components functioning as a single unit
• Systems have boundaries; everything outside is the environment

General Representation of a System

• A Diagram showing parts of a system, including components, links, interfaces, and the environment surrounding it (with an encompassing boundary)

Definition of an Interface

• Boundary between two or more components of a computer system for exchanging information

Different Interfaces

• A diagram showing various computer interfaces like Ethernet, USB, Wi-Fi, and others

A Simple E-Business System

• A diagram representing a basic business structure showing components (suppliers, customers, employees, marketing, finance) and their relationships

System Decomposition

• Breaking down a system into smaller, simpler components and their relationships

Hierarchy of the Internet

• Diagram illustrating a layered hierarchy of internet connections

System Architecture

• Defines the fundamental properties, relationships, connections, constraints, and interlinkages within the system and its environment

Abstractions of Systems

• Models or simplified representations of a complex system (not literal representations/are not the same as the real system)
• Examples of system representations for various systems/abstractions

Abstractions of Systems

• The differences between various system abstractions and real-world systems are discussed

Business Organization Chart

• A hierarchical organizational chart for a business, showing departments and sub-departments

Business Application Architecture

• A diagram of a business application architecture, showing the flow of information between different applications and systems

Summary (2.2)

• Defines a system as a group of components functioning together
• System architecture defines the relationships between components and the system/environment
• System abstraction is a simplified representation of a system

2.3: IT System Architecture

• Covers IT system architecture in detail

Learning Objectives (2.3)

• Explain the purpose of IT system architectures
• List three types of distributed processing systems
• Describe client-server, cloud, and peer-to-peer computing structures
• Give examples of client-server architecture
• Compare the three types of cloud computing services

Application Architecture

• Characterized by the flow or processing of data: within an organization, between organizations, and between an organization and its environment

IT System Architectures

• IT systems are complex and multi-layered—consisting of various subsystems

Distributed Processing Systems

• Describes three types of distributed processing systems: client-server, cloud, and peer-to-peer

Client-Server Computing

• Architecture where one computer (server) provides services to multiple computers (clients)
• Examples include email, files, printing, web browsing, database access, and remote access services

Basic Two-tier Client-Server Architecture

• A simple diagram showing two computers communicating
• The server and client exchange requests and responses via a communication channel

Web Browser-Web Server Model

• An illustration showing the interaction between a web browser (client) and a web server

Clients and Servers on a Network

• Dedicated servers run a single service
• Shared servers run multiple services (e.g. databases, emails)

Advantages of Client-Server Architecture

• Centralized service administration
• Easier service availability/location for users
• Consistent resources management

Multi-tier Architectures

• Models where multiple computers participate in a service:
  • Two-tier: two computers involved
  • Three-tier: three computers involved
  • N-tier: any number of computers involved

Multi-tier Architectures: Two-tier

• Diagram of two-tier architecture (client-server)

Multi-tier Architectures: Three-tier

• Diagram of three-tier architecture (client-web server-database server)

Three-tier Web-based Email Architecture

• Diagram of a three-tier web-based email system illustrating the interaction between the client, web server, and the mail server

Multi-tier Architectures: N-tier

• Diagram illustrating N-tier architecture, where multiple tiers of applications and services are involved.
• Advantages of N-tier are easier upgrades and improved scalability

Cloud Computing (1 of 2)

• Describes the concept including the core components of cloud computing (servers, virtual desktops, applications, software platforms, and storage).
• Includes a diagram illustrating the user components and the cloud components

Cloud Computing (2 of 2)

• Three core types of cloud services: Software as a service, platform as a service, and infrastructure as a service

Software as a Service (SaaS)

• Applications running on a server, processing may be divided between server and client

Platform as a Service (PaaS)

• Hosting for applications and services, virtual hosting of websites, databases, and operating systems

Infrastructure as a Service (IaaS)

• Virtualized hardware resources including computing, network, and storage systems

Peer-to-Peer Computing

• Computers treated as equals in a network, sharing resources

Peer-to-Peer Computing: Disadvantages

• Difficulty locating services
• Difficult to synchronize files/software
• Hard to secure network
• Potential for viruses/malware issues

Peer-to-Peer Computing: Advantages

• Easy setup without a server
• Sharing files between computers
• If a computer goes offline, files remain available on others

Hybrid Model of Computing

• Use of client-server technology to locate systems and files, with the ability to transition to peer-peer sharing

Summary (2.3)

• Describes different IT models for application and system design—client-server, cloud, and peer-to-peer
• Highlights the aspects and advantages of each model