Advanced Business ICT and Computer Systems Study Guide

INFORMATION AND COMMUNICATIONS TECHNOLOGY (ICT) OVERVIEW

• Extended Synonym for IT: ICT is an extensive term that stresses the role of unified communications and the integration of telecommunications (telephone lines and wireless signals). It encompasses computers, enterprise software, middleware, storage, and audio-visual systems.
• Functionality: These technologies enable users to access, store, transmit, and manipulate information.
• Convergence: The term refers to the convergence of audio-visual and telephone networks with computer networks through a single cabling or link system. This offers large economic incentives due to cost savings from eliminating redundant telephone networks.
• Evolutionary Definition: ICT has no universal definition because the concepts, methods, and applications are constantly evolving on an almost daily basis. The scope covers any product that stores, retrieves, manipulates, transmits, or receives information electronically in digital form, such as personal computers, digital television, email, and robots.

COMPONENTS OF ICT AND MODERN TECHNOLOGIES

• Information Technology (IT): The application of computers and telecommunications equipment to store, retrieve, transmit, and manipulate data, primarily within business or enterprise contexts.
• Associated Industries: Includes computer hardware, software, electronics, semiconductors, the internet, telecom equipment, engineering, healthcare, e-commerce, and computer services.
• Significant Historical Identification (James William, 1982): Identified six major technologies relevant to modern information systems:
  • Processors, memory, and input/output ($\text{I/O}$) channels.
  • Micro, mini, and large-scale computers.
  • Mass storage technologies.
  • Data communication, networking, and distributed processing.
  • Data entry and display response.
  • Software.
• Primary Groupings:
  • Computer Technology: Involves scientific databases, microchip technology, artificial intelligence, and machine-readable databases.
  • Communication Technology: Includes audio technology (FM receivers replacing outmoded AM), audio-visual technology (videodiscs for high-quality storage and image stability), facsimile transmissions (Fax) using data compression, and electronic mail (point-to-point message systems).
  • Reprographic, Micrographic, and Printing Technologies: Facilitates resource sharing and storage solutions through condensation (e.g., microforms like microfilm and microfiche).

MICROFORMS AND PRINTING TECHNOLOGY

• Microforms: A term for micro-documents in transparent or opaque, roll, or sheet forms. Varieties include microfilm, microfiche, ultra-fiche, and micro-opaque cards.
  • Roll-film (Microfilm): A continuous strip of film (typically $100\,\text{feet}$ long and $35\,\text{mm}$ wide) with images in sequence.
  • Microfiche: A flat film containing a large number of images in rows and columns. A standard $4 \times 6\,\text{inch}$ microfiche accommodates $98\,\text{pages}$.
• Printing Technology History: From manual record-keeping to lasers and computers. Modern computer printers fall into three categories: line printers, dot matrix printers, and laser printers (the most popular today).

THE ICT SYSTEM STRUCTURE

• System Definition: A set-up consisting of hardware, software, data, and people. While computers are hardware, they are only a part of the overall ICT system.
• Application Environments: Used in offices, shops, factories, aircraft, and ships. Fields of application include communications, medicine, and farming.
• Core Benefits:
  • Increased productivity (more tasks completed in less time at reduced cost).
  • Ability to process and transmit vast amounts of information rapidly.

TYPES OF ICT SYSTEMS

• Information Systems: Focused on managing data and information. Examples include a supermarket stock system or a sports club membership system.
• Control Systems: Primarily control machines. Output might involve physical movements, such as a robot arm welding a car chassis.
• Communications Systems: The primary output is the successful transport of data from one location to another.

INPUT, OUTPUT, AND SYSTEM DYNAMICS

• System Mechanism: Takes inputs (instructions and data), processes them, and produces outputs for storage or communication.
• Garbage In, Garbage Out (GIGO): If inputs are inaccurate or faulty, the system will output erroneous or useless data. This makes data validation and accuracy essential.
• Feedback Loops: When output from a system influences subsequent input to repeat a process.
  • Tropical Fish Tank Example: Sensors take water temperature as input. Processing compares the temperature against pre-programmed maximum/minimum parameters. The output is the decision to turn the heater on or off. The resulting change in temperature is sensed again as input, repeating the cycle.
  • Information System Example: Accepting an online flight booking (output) results in a reduction of available tickets for future bookings (input).

ICT IN MODERN ORGANIZATIONS

• Communication: Transitioned from physical mail to email, live chat, online meeting tools, video conferencing, and Voice over Internet Protocol ($\text{VoIP}$).
• Inventory Management: Systems track quantities and trigger orders when stock falls below pre-determined levels. Connection to Point-of-Sale ($\text{POS}$) systems creates a closed information loop.
• Data Management: Shift from physical filing cabinets to digital servers, making historical data economically stored and accessible regardless of geographical location.
• Management Information Systems (MIS): Tracking sales, expenses, and productivity to maximize return on investment ($\text{ROI}$) and identify improvements.
• Customer Relationship Management (CRM): Capturing every interaction with a customer to provide a focused experience (e.g., support staff viewing purchase and shipping history).
• Business Marketing: Use of the World Wide Web and Quick Response ($\text{QR}$) codes to advertise and take orders online.

IMPACT OF ICT ON SOCIETY AND ORGANIZATIONS

• Positive Impacts on Individuals:
  • Increased access to services (VoIP, Instant Messaging).
  • Opportunities for leisure, entertainment, and worldwide relationships.
  • Improved education via distance learning and interactive multi-media.
  • Tools for overcoming disabilities (e.g., screen reading software for the blind).
• Negative Impacts on Individuals:
  • Job loss due to automation or "job export" to lower-cost countries.
  • Reduced personal interaction and social isolation.
  • Health risks from sedentary lifestyles, such as obesity and heart disease.
• Organizational Impacts:
  • Positive: Cost savings (e.g., email instead of post), 24-hour worldwide market access, and data mining for targeted advertising.
  • Negative: High costs of hardware/software maintenance, daily threats from viruses/malware, and intense competition from global rivals.
• Educational Impacts:
  • Digital Divide: Poorer students may be disadvantaged by high technology costs.
  • Mixed Results: While simulations improve science standards and word processors help language skills, the mere presence of ICT does not guarantee better learning unless teaching methods adapt.

COMPUTER SYSTEMS AND COMPUTERIZATION

• Definition: A computer is a device that receives, processes, and stores data. A computer system is a network of interconnected computers sharing central storage and peripheral devices like printers or routers.
• Computerization Advantages:
  • Reduced response time.
  • Improved accuracy and decision quality.
  • Enhanced secrecy compared to manual file systems.
• Computerization Disadvantages:
  • Increased unemployment.
  • Time wastage (e.g., social media/gaming distracts from studies).
  • Data security risks (hacking, credit card theft).
  • Health risks (Repetitive Strain Injury, eyestrain).
• Environmental Impact: Manufacturing and waste pollute the environment with toxic materials. "Green computing" aims to reduce electricity consumption and waste through recycling.

EVOLUTION AND GENERATIONS OF COMPUTERS

• Historical Milestones:
  • 1870s: Typewriter development.
  • 1920s: Invention of the telephone ($\text{LAN/WAN}$ communication).
  • 1940s: First electronic computers developed; operations research applied to decisions.
  • 1960s: Emergence of MIS.
  • 1970s: Widespread use of word processors, PCs, and spreadsheets.
  • 1980s: Office automation combining data, text, graphics, and voice.
  • 2000s: Massive expansion of e-commerce, e-learning, and e-health.
• Computer Generations:
  • First Generation ($1946 \text{--} 1957$): Used vacuum tubes. Large, slow, and consumed high power. Difficulty in switching between programs.
  • Second Generation ($1958 \text{--} 1964$): Replaced vacuum tubes with transistors (smaller, cheaper, less heat). Concept of $\text{CPU}$, memory, and high-level languages like $\text{COBOL}$ and $\text{FORTRAN}$ emerged.
  • Third Generation ($1965 \text{--} 1971$): Used Integrated Circuits ($\text{IC}$). Smaller size, larger memory, and higher processing speeds (up to $1\,\text{MHz}$).
  • Fourth Generation ($1972 \text{--} \text{Present}$): Uses Large Scale Integration ($\text{LSI}$) and Very Large Scale Integration ($\text{VLSI}$). Speeds up to $10\,\text{MHz}$.
  • Fifth Generation ($1990\text{s} \text{--} \text{Present}$): Focuses on Very Large Scale Integration ($\text{VLSI}$), speeds above $400\,\text{MHz}$, parallel processing, and Artificial Intelligence ($\text{AI}$).

CLASSIFICATION OF COMPUTERS

• By Processing Style:
  • Digital: Processes discrete values (e.g., $0, 1, 2$); used for business and high-accuracy science.
  • Analog: Processes physical variables; outputs are typically smooth graphs (scientific/engineering use).
  • Hybrid: Combined features of digital and analog.
• By Purpose:
  • Special Purpose: Specific functions (medicine, manufacturing).
  • General Purpose: Wide variety of tasks (word processing, accounting).
• By Configuration/Power:
  • Supercomputers: Largest/most powerful for complex data (meteorology/astronomy). Examples: Cray, Fujitsu.
  • Mainframes: Large, centralized processing for major commercial organizations (e.g., IBM).
  • Minicomputers: "Midrange" computers for specific departments or small businesses.
  • Microcomputers: Widely used and fastest-growing category (Laptops, Desktops, Smartphones, Tablets).

DATA AND INFORMATION REPRESENTATION

• Data vs. Information: Data is raw facts/figures. Information is processed data that is timely, accurate, and complete, serving as the basis for decisions.
• Data Processing Cycle: Input (preparation of data) \rightarrow Processing (manipulation) \rightarrow Output (collection of results).
• Internal Storage Format: Computers use binary (base two) sequences of $0\text{s}$ and $1\text{s}$.
  • Bit: A single binary digit ($0$ or $1$).
  • Byte: $8\,\text{bits}$; represents $2^{8} = 256$ pieces of information.
  • Word: A fixed number of bits processed as a unit (e.g., $8, 16, 32, 64$, or $96\,\text{bits}$).
• Text Representation: $\text{ASCII}$ (American Standard Code for Information Interchange) assigns codes $0\text{--}127$ for standard characters. Uses $1\,\text{byte}$ per character.
• Graphics Representation: Images consist of pixels (dots of color).
  • Resolution: E.g., $800 \times 600$ pixels.
  • Color Depth: Monochrome requires $1\,\text{bit}$ per pixel; $24\text{-bit}$ color offers $16.7\,\text{million}$ colors.
• Compression: Making files shorter by removing bit redundancies to save storage space and transmission time.

NUMBER SYSTEMS AND CALCULATIONS

• Decimal System: Base $10$ (digits $0\text{--}9$). Successive positions represent powers of $10$ (units, tens, hundreds).
• Binary System: Base $2$ (digits $0, 1$). Standard computer language.
• Octal System: Base $8$ (digits $0\text{--}7$).
• Hexadecimal System: Base $16$ (digits $0\text{--}9$, and letters $A\text{--}F$ where $A=10$ and $F=15$).
• Decimal to Other Base Conversion Process:
  1. Divide the decimal number by the new base.
  2. The remainder becomes the least significant digit ($\text{LSD}$).
  3. Divide the quotient by the base again.
  4. Repeat until the quotient is zero. Arrange remainders in reverse order for final value.
  • Example ($29_{10}$ to Binary):
    • $29 / 2 = 14\,\text{rem } 1$
    • $14 / 2 = 7\,\text{rem } 0$
    • $7 / 2 = 3\,\text{rem } 1$
    • $3 / 2 = 1\,\text{rem } 1$
    • $1 / 2 = 0\,\text{rem } 1$
    • Result: $11101_{2}$.
• Other Base to Decimal Conversion Process:
  1. Determine the column value ($\text{base}^{\text{position}}$).
  2. Multiply the digit by its column value.
  3. Sum the products.
  • Example ($11101_{2}$ to Decimal):
    • $(1 \times 2^{4}) + (1 \times 2^{3}) + (1 \times 2^{2}) + (0 \times 2^{1}) + (1 \times 2^{0}) = 16 + 8 + 4 + 0 + 1 = 29_{10}$.

SIX ELEMENTS OF THE COMPUTER SYSTEM

1. Hardware: Physical tangible components (Monitors, Keyboards, Processors).
2. Software: Programs that interface between hardware and users. Types include System Software, Application Software, Operating Systems, Utility Software, Language Processors, and Connectivity Software.
3. People (Live-ware): Users, System Analysts (designers), System Programmers (coders), and System Operators (end-users).
4. Procedures: Step-by-step instructions (Hardware-oriented, Software-oriented, and Internal procedures).
5. Data: Raw facts/figures interpreted by machine language to become information.
6. Connectivity: The linking of computers to share resources via wires, cables, satellites, infra-red, Bluetooth, etc.

CENTRAL PROCESSING UNIT (CPU) COMPONENTS

• Arithmetic and Logic Unit (ALU):
  • Arithmetic Section: Performs addition, subtraction, multiplication, and division.
  • Logic Section: Performs comparisons, matching, and merging data.
• Control Unit (CU): Coordinates all activities. It decodes instructions, manages data transfer among units, and communicates with $\text{I/O}$ devices.
• Memory/Storage Unit: Stores internal data. Size affects the computer's speed and capability.

COMPUTER HARDWARE: INPUT AND OUTPUT DEVICES

• Input Devices:
  • Keyboard: Common sizes are $84, 101/102, 104$, or $108\,\text{keys}$. Includes typing keys, numeric keypad, function keys ($F1\text{--}F12$), and control keys.
  • Mouse: Pointing device with a ball or sensor. Offers left/right buttons and a scroll wheel.
  • Joystick: Moves cursor positions using a spherical ball in a socket; primarily for CAD and gaming.
  • Scanner: Converts paper-based info into digital images for internal storage and manipulation.
  • Digitizer (Graphics Tablet): Converts analog signals (from TV/camera/drawing) into binary series ($0\text{s}$ and $1\text{s}$).
  • Magnetic Ink Character Recognition (MICR): Used in banks for fast, error-free check processing using magnetic ink.
  • Optical Mark Reader (OMR): Recognizes pen/pencil marks on exams or surveys.
• Output Devices:
  • Monitors (VDU):
    • Cathode-Ray Tube (CRT): Uses illuminated pixels; large and consumes high power.
    • Flat-Panel Display: Includes $\text{LCD}$ (non-emissive) and $\text{LED/Plasma}$ (emissive).
  • Printers:
    • Impact Printers: Physical contact with paper. Examples: Dot Matrix (pattern of dots), Daisy Wheel (petal-shaped head), Drum and Chain (line printers).
    • Non-Impact Printers: No ribbon contact. Examples: Laser Printers (use laser light, high speed, high quality) and Inkjet (spraying ink drops; quiet and supports color).
• Communication Devices:
  • Network Interface Card (NIC): Handles physical network signals.
  • Modem: Performs Modulation (digital to analog) and Demodulation (analog to digital) for telephone line transmission.
  • Router: Directs network traffic based on $\text{IP}$ addresses.

MEMORY CLASSIFICATION AND STORAGE

• Cache Memory: High-speed semiconductor buffer between the $\text{CPU}$ and main memory. Fast but expensive and limited in capacity.
• Primary Memory (Main Memory):
  • RAM (Random Access Memory): Volatile (data lost when power is off); Read/Write memory. Types include SRAM (static, no refresh needed, used as cache) and DRAM (dynamic, needs continuous refreshing, cheaper and used for system memory).
  • ROM (Read Only Memory): Non-volatile; used for bootstrap instructions to start the computer. Types include $\text{PROM}$ (programmable once), $\text{EPROM}$ (erasable by $\text{UV}$ light), and $\text{EEPROM}$ (electrically erasable; flexible but slow).
• Secondary Memory: Non-volatile, magnetic, or optical (Hard disks, $\text{CDs, DVDs}$). Slower than primary memory but stores data permanently.
• Storage Units:
  • $1\,\text{Kilobyte (KB)} = 1024\,\text{Bytes}$
  • $1\,\text{Megabyte (MB)} = 1024\,\text{KB}$
  • $1\,\text{Gigabyte (GB)} = 1024\,\text{MB}$
  • $1\,\text{Terabyte (TB)} = 1024\,\text{GB}$

SYSTEM PORTS AND CONNECTIVITY

• Serial Port: For external modems and older mice ($9\text{-pin}$ or $25\text{-pin}$). Speed: $115\,\text{kbps}$.
• Parallel Port: For scanners and printers ($25\text{-pin}$ Centronics port).
• USB Port: Universal Serial Bus; introduced in $1997$. Connects various devices at $12\,\text{Mbps}$.
• VGA Port: $15\text{-hole}$ connector for monitors.
• FireWire (IEEE 1394): Invented by Apple; transfers data at $400\text{--}800\,\text{Mbps}$ for video equipment.
• Ethernet Port: For networking; speeds from $10\text{--}1000\,\text{Mbps}$.

COMPUTER SOFTWARE AND PROGRAMMING

• Operating Systems (OS): A program that manages hardware resources and provides common services. Functions include memory management, processor scheduling, $\text{I/O}$ management, and file system manipulation.
• Software Types:
  • Proprietary: Legal property of one party; highly customized but expensive/risky.
  • Off-the-shelf: Ready-made for public sale; cheaper and pre-tested but may have irrelevant features.
• Programming Language Generations:
  • $1^{st}$ Generation (Machine Language): Binary ($0, 1$). Fast but complex and machine-dependent.
  • $2^{nd}$ Generation (Assembly Language): Uses symbolic codes/mnemonics. Requires an assembler for translation.
  • $3^{rd}$ Generation (High-Level/Procedural): English-like statements ($\text{Basic, COBOL, C, FORTRAN}$). Easier but slower; requires a compiler.
  • $4^{th}$ Generation ($4GLs$/Non-Procedural): Focuses on what to do rather than how (e.g., $\text{SQL}$ for databases).
  • Object-Oriented Programming (OOP): Items are "objects" containing data and operations ($\text{encapsulation}$). Promotes code reuse and easier maintenance.
• Language Translators:
  • Interpreters: Translate and execute one statement at a time; slow but good for debugging.
  • Compilers: Convert the entire source code into an object module at once for faster execution.

OPERATING SYSTEM DYNAMICS AND BOOTING

• Process States: New (being created), Ready (waiting for assign), Running (executing), Waiting (event wait), and Terminated (finished).
• Process Control Block (PCB): A data structure storing process state, program counter, $\text{CPU}$ registers, and memory management info.
• Schedulers:
  • Long Term (Job Scheduler): Selects jobs from the pool to load into memory.
  • Short Term (CPU Scheduler): Selects process to execute next (dispatcher).
  • Medium Term: Handles swapping processes between memory and disk.
• Booting Sequence:
  1. Power button turned on.
  2. $\text{CPU}$ registers set to specific values; jump to BIOS address ($0xFFFF0$).
  3. BIOS runs $\text{POST}$ (Power-On Self Test).
  4. BIOS searches for $\text{MBR}$ (Master Boot Record).
  5. $\text{PBL}$ (Primary Bootloader) from $\text{MBR}$ jumps to Secondary Bootloader.
  6. Secondary Bootloader loads the $\text{OS}$.

COMPUTER FILES AND DATA PROCESSING

• File Elements: Identifiers (name), Size (bytes), Date, Author, Organization (access mode), Volatility (frequency of change), and Hit Rate (measure of active record processing).
• File Organization:
  • Serial: Records in turn; high access time. Used for temporary work files.
  • Sequential: Organized by an ascending key; used for master files in batch processing.
  • Indexed-Sequential: Sequential but with an index for direct access; most common.
  • Random: Location determined by a randomizing algorithm for fast direct access.
• Data Processing Stages: Collection \rightarrow Preparation \rightarrow Input \rightarrow Processing \rightarrow Output/Interpretation \rightarrow Storage.

INFORMATION SYSTEMS (IS) CLASSIFICATION

• Transaction Processing Systems (TPS): Record daily routine business exchanges (ATMs, airline reservations).
• Management Information Systems (MIS/MRS): Provide routine, structured reports for operational monitoring (scheduled, demand, and exception reports).
• Decision Support Systems (DSS): Help with non-routine, complex decisions through modeling and "What If" analysis.
• Executive Support Systems (ESS/EIS): Menu-driven summary information for top executives with interactive graphics.
• Expert Systems (ES): Advanced systems utilizing Artificial Intelligence to provide expert-level advice via a knowledge base and inference engine.
• Enterprise Resource Planning (ERP): Unified set of programs handling key business processes across all locations ($\text{ORACLE, SAP, PeopleSoft}$).

COMPUTER NETWORKS AND TOPOLOGIES

• Classifications by Size:
  • LAN (Local Area Network): Close physical proximity (single office/building).
  • MAN (Metropolitan Area Network): Citywide; links office buildings across a city.
  • WAN (Wide Area Network): Countrywide or worldwide (e.g., the Internet).
• Networking Hardware:
  • Hub: Unintelligent; sends signal to all connected ports (Layer $1$).
  • Switch: Intelligent; gives switched connections to prevent collisions (Layer $2$).
  • Bridge: Connects two $\text{LANs}$ and filters packets (Layer $2$).
  • Repeater: Boosts/regenerates signal between segments (Layer $1$).
  • Router: Connects multiple $\text{LANs}$ based on $\text{IP}$ addresses (Layer $3$).
• Network Topologies:
  • Star: All nodes link to a central hub. Easy to add nodes but the center is a single point of failure.
  • Bus: Nodes link along a common connecting backbone. Least cable used but difficult to troubleshoot.
  • Ring: Each device connects to two others in a circle. High performance but one failure can affect the whole ring.
  • Mesh: Multiple redundant interconnections. Greatest redundancy but highest installation cost.

THE OSI MODEL SEVEN LAYERS

1. Physical Layer: Raw bit stream transmission over a physical medium (baseband or broadband).
2. Data Link Layer: Error-free transfer of data frames between nodes.
3. Network Layer: Routing of data and logical-physical address mapping.
4. Transport Layer: Ensures messages are delivered error-free, in sequence, with no losses.
5. Session Layer: Establishes, maintains, and terminates connections between processes.
6. Presentation Layer: Translator for the network (data formatting, compression, encryption).
7. Application Layer: Window for users to access network services (Electronic messaging, remote file access).

CLOUD AND MOBILE COMPUTING

• Cloud Computing Services:
  • SaaS (Software as a Service): Applications run on distant computers (e.g., $Facebook, Google Docs$).
  • PaaS (Platform as a Service): Environment for building/delivering web applications without managing underlying hardware.
  • IaaS (Infrastructure as a Service): Pay-per-use computing resources like servers and storage.
• Deployment Models: Public Cloud (open to public), Private Cloud (single organization), and Hybrid Cloud (integration of both).
• Mobile Computing: Transmission of data/voice/video via wireless devices. Limitations include narrow bandwidth (compared to cables), power consumption (battery reliance), and transmission interferences (weather/terrain).

THE INTERNET AND EMERGING TRENDS

• World Wide Web (WWW): Created by Tim Berners-Lee approx. $1990$. Organizes the internet into websites and pages using $Hypertext Transfer Protocol (HTTP)$.
• Internet History: Started as Arpanet ($1969$). Switch to $TCP/IP$ occurred on January $1, 1983$. Publicized by $\text{CERN}$ in $1991$.
• Intranets vs. Extranets: Intranets are private organizational networks. Extranets allow specific outside people (suppliers/remote staff) limited access to the intranet, often via a Virtual Private Network ($\text{VPN}$).
• Search Engines: Use search terms/keywords to find relevant content. Boolean operators include $\text{AND (+), OR, and NOT (-)}$.
• ISPs (Internet Service Providers): Use $\text{Point to Point Protocol (PPP)}$ to connect users to the internet. Connection types include Dial-up ($56\,kbps$ max), $DSL$ (digital over phone lines), Cable Modem (via cable $\text{TV}$ infrastructure), and $VSAT$ (satellite communication).
• Emerging Trends:
  • Analytics: Data, Predictive, and Social media analytics to discover informational patterns.
  • User Interfaces: Revolutionized by touch screen capabilities.
  • Mobile Apps: Success of downloading software for smartphones/tablets.