SUMMARY FINAL IT PDF

# Lecture 1: Tools for an Information Age **Literacy is:** (Awareness - Knowledge - Interaction) - **Awareness:** You understand the importance of computers. - **Knowledge:** You understand how to use computers. - **Interaction:** You are a producer and have a product. ## Two identifications of Co...

# Lecture 1: Tools for an Information Age **Literacy is:** (Awareness - Knowledge - Interaction) - **Awareness:** You understand the importance of computers. - **Knowledge:** You understand how to use computers. - **Interaction:** You are a producer and have a product. ## Two identifications of Computers: 1. Electronic device that processes given data to derive the required. 2. Machine that can be programmed to accept data and store it. ## Three Main Functions of a Computer: 1. Input 2. Process 3. Output ## Important Question: - **Input:** Receives data. - **Process:** Data processing. - **Output:** Produces information. ## Two Components to Complete the Function: 1. **Hardware:** Input, processing unit, output, memory, storage. 2. **Software:** System, application. # Lecture 2: Applications Software **Applications:** - Used to solve a problem. - Perform a task. ## Acquiring Software - **Traditional Ways** - **Custom Software** - Written by programmers for a specific organization. - Designed to meet specific needs. - Complex. - **Packaged Software** - Available from a store or website. - Downloaded from the internet. - User-friendly. - Includes software documentation. - **New Ways** - **Freeware** - Retains copyright. - Restrictions on its use. - **Public Domain** - Not copyrighted. - No permission needed. - Usually developed by government grants. - **Open-Source** - Code made available and readable. - Modify and redistribute. - **Shareware** - Copyrighted, but freely distributed for a trial period. ## Buying Commercial Software - **Individual Copies** - **Site License:** Installed on some or all computers, with a track record of how many users. **Electronic Software Distribution:** - From the internet - Usually Freeware and Shareware ## Typical Scenarios: - Trial Period. ## Task-Oriented Software - **Productivity Software** - Word Processing - Desktop Publishing - Electronic Spreadsheets - Database Management - Graphics - Communications - **Other Task Software** - Office Suite - Personal Information Managers (PIM) ## Business Software - **Vertical Market Software:** - Type of business only. - Used by companies. - **Software for Work Groups** - Remote Employees - Small Business: Small home office (SOHO) - Accounting, Writing, Customer Keeping. ## Ethics and Applications # Computer Professionals - **Data Entry Operators:** Data for processing. - **Computer Operators:** Monitor, running, backups. - **Librarians:** Catalogs, tapes. - **Programmers:** Write, test, implement, maintain. - **Systems Analysts:** Plan and design. - **Network Managers:** Implement and maintain. - **Chief Information Officer:** Strategic Decisions. # Lecture 3: Operating System ## Systems Software: - Coordinates computer operations. - Operating Languages. - Translators. - Utility Programs. ## Operating System: - Lies between Applications and hardware. - Manages computer resources: CPU, peripherals. - Establishes a user interface for interaction with operating software. - Provides services for applications software. ## Kernel: - The most important program. - Manages the operating system. - From hard drive to memory. - **Bootstrapping**: Starting the computer. ## Operating System for Personal Computers - **Platform** - Hardware and operating system. - **Wintel** - **Common Platforms:** MS-DOS, Windows, Mac. ## File Management: - File: Storage device. - Folders: Organize files and have subfolders. - **Path to Find a File:** Primary -> Secondary -> Tertiary -> File. ## File Naming Conventions: - Each file needs a file name (Name.Extension). - Extension identifies the type of data. ## File Management Utilities: - My computer is the main file management utility. - Creating folders. - Transferring: Two basic ways. ## Utility Programs (Secondary Chores): - File Compression - Backup and Restore - Anti-Virus - Disk Defragmenter # L141: CPU ## Central Processing Unit: - Electronic circuitry. - Executes stored program instructions (ESPI). - Two parts: Control Unit, ALU. ### Control Unit: - Directs the computer system to ESPI. - Communicates with memory and ALU. - Sends data from secondary to primary memory. ### Arithmetic Logic Unit: - Executes all arithmetic and logic operations. - **Arithmetic Operations:** Addition, subtraction, division, multiplication. - **Logical Tests:** Equal to, Less than, Greater than. ## Two Types of Storage: 1. **Primary Storage (Memory)**: - RAM. - Not part of CPU. - Data, program instructions are stored here. 2. **Secondary Storage:** - Long term. - External medium. ## CPU and Memory: - CPU cannot process data, but it must first reside in memory. - Control Unit: Data from disk into memory. - Control Unit: Sends ALU results to memory after processing. ## How the CPU Executes Instructions: - Four steps performed per instruction. - Called "Machine Cycle." - Personal: Less than one millionth of a second. - Super: Less than one trillionth of a second. ## Machine Cycle: - Time required to: Fetch, decode, store, execute. - Components: Instruction time, Execution time. - **Instruction Time:** - Control unit gets instruction from memory. - Control unit determines the memory location. - **Execution Time:** - Control unit data from memory to ALU. - Control unit stores the result of the operation. ## Data Representation: - Computers understand two things: on, off. - Binary (base 2): 0 and 1. - Representing data: Bit, Byte, Word. - **Bit**: (0 or 1) Never be empty. - **Byte:** Group of 8 bits. 256 (2^8) possible values. Stores one character. - Memory and storage are measured in number of bytes. ## Storage Sites: - **Kilobyte:** Capacity of a personal computer. - **Megabyte:** Personal, diskette, CD-ROM. - **Gigabyte:** Hard drives, mainframe, network server. - **Terabyte:** Very large systems. ## Word: Number of bits. - The CPU. - Whole number of bytes. - Large word: More powerful. - Personal computer: 32 or 64 bits in length. ## System Unit: - Motherboard: Circuit board, microprocessor. - Microprocessor: Most important. Silicon chip, Millions of tiny transistors. - Transistors: May or may not allow current to pass. ## RAM: - Random. - **SIMMS:** Single line. - **DIMMS:** Dual line. - **Types:** Static (SRAM), Dynamic (DRAM). - Circuit boards. ## ROM: - **Read only:** Recorded into memory at the factory. - Permanent. - **Non-volatile:** Cannot be changed. - Some instructions on chip can be changed. ## The System Bus: - Parallel electrical paths that transport data between CPU and memory. - **Bus speed:** Megahertz. Faster: P2 400, 1533 MHz. - **Bus width:** Carries data, bits. Large bus size is the same as CPU's word size. Allows for more memory. ## Expansion Buses: - Port, expansion board, and common connections. - Ports: External connectors to plug in printers. - **Serial:** Transmits data one bit at a time. Slow devices: mouse, keyboard. - **Parallel:** Transmits data groups of bits together. Side by side, faster: Printers, scanners. ## Common Expansion: - Industry standard (ISA): Slow devices. - Accelerated graphics ports (AGP): Faster video. - Peripheral component interconnect (PCI): Universal serial bus (USB), USB port. ## Cache: - Temporary Storage within the computer. - **Memory Cache:** Small block, high speed. Most frequently and recently accessed data is here. - **Processor Cache:** - Internal (L1): Highest cost, fastest access. Microprocessors. - External (L2): Separate chip. ## Pielining: - Parallel processing. # Chapter 15: Computer Connections - **A collection of two or more computers linked together to exchange data and resources.** ## Benefits of Networks: - **Resource Sharing:** Hardware and software. - **Computation Speedup:** Distribute computations. - **Load Balancing:** Tasks highly loaded and lightly loaded. - **Communication:** Email, Chatting. ## Network Types: Based on geographical connectivity, network structure. - **Personal Area Network (PAN):** One person. Range: 10m. Ex: Mouse, keyboard, printers. - **Local Area Network (LAN):** Small geographical privately owned - **Metropolitan Area Network (MAN):** Large geographical. Ex: Network in a city. - **Wide Area Network (WAN):** Unlimited geographical. Consists of multiple LANs. Lower speed, higher error. Ex: Country or globe. ## Network Topology: - **Physical layout**, node: Each computer. - **Common Topologies:** Bus, star, ring. ## Network Structure: - **Peer-to-peer:** Less expansive, small size, distributed resources, difficult to be controlled, no servers, all computers. - **Server-based:** High expansive, open size, centralized resource, easy to control, has server, power, and computers. ## Server Types: - **File server:** Shared files and backups. - **Printer server:** Different clients use the same printer. - **Mail server:** Store and forward email. - **Web server:** Store and shared web pages. - **Database server:** Store database files. - **Proxy server:** Protect the network. ## Connectivity: - **Wired:** Uses wires to connect network computers. - **Wireless:** No wiring. Done using radio signals. Done via base station. Ex: Bluetooth, LAN, WAN. ## Simplex Transmission: - Only one direction. Ex: Television broadcasting. - **Half Duplex:** Both directions, but not at the same time. Ex: Walkie-talkie. - **Full Duplex:** Both directions, at the same time. Ex: Conversation. ## Interconnecting Devices: - **Routers:** Transmit and send data to its destination. - **Switch:** High speed connection between computers. - **Modem:** Modulates (digital to analog) and demodulates (analog to digital). - **Bridge:** Connects similar networks. - **Network Interface card (NIC).** ## Protocol: - How network components communicate with each other. - **Transmission control protocol (TCP):** - **Internet Protocol (IP).** # SAQ: Final it ## Computer Networks: - **Define:** Collection of two or more computers linked together to exchange data and resources. ## Classification: - **Geographical:** (PAN, LAN, MAN, WAN). - **Network Structure:** (Peer-to-peer, Server-based). - **Connectivity:** (Wired, Wireless). ## Benefits: - **Resource Sharing** - **Communication** - **Computation Speedup** - **Load Balancing**