IT Reviewer PDF

#### IT REVIEWER Technology -is also allowing us to redefine fundamental parts of our social makeup---how we think, how we connect with each other, and how we purchase and consume products. COMPUTER-is a programmable, multiuse machine that accepts data --- raw facts and figures ---and processes, o...

#### IT REVIEWER Technology -is also allowing us to redefine fundamental parts of our social makeup---how we think, how we connect with each other, and how we purchase and consume products. COMPUTER-is a programmable, multiuse machine that accepts data --- raw facts and figures ---and processes, or manipulates, it into information we can use. COMMUNICATIONS TECHNOLOGY- also called telecommunications technology, consists of electromagnetic devices and systems for communicating over any distance+. 10 COMMANDMENTS OF COMPUTER ETHICS harm 1. Thou shalt not use a computer to harm other people. interface 2. Thou shalt not interfere with other people's computer work. snoop 3. Thou shalt not snoop around in other people's computer files. steal 4. Thou shalt not use a computer to steal. false witness5. Thou shalt not use a computer to bear false witness. not paid 6. Thou shalt not copy or use proprietary software for which you have not paid. authorization 7.Thou shalt not use other people's computer resources without authorization or proper compensation. intellectual output 8.Thou shalt not appropriate other people's intellectual output. designing. 9.Thou shalt think about the social consequences of the program you are writing or the system you are designing. respect10.Thou shalt always use a computer in ways that insure consideration and respect for your fellow human COMPUTER is derived from the word 'compute' which means to calculate. Abacus- the abacus was the first mechanical device for calculation which could also perform arithmetic. Pascaline by Louis Pascal the Pascaline is the first mechanical calculator in the world. the Pascal line was invented by a French mathematician called Louis Pascal in 1642 and so it is named after him. Charles Babbage "Father of Computer" Charles Babbage was a British mathematician who designed the analytical engine in 1833 Analytical Engine- the analytical engine is an engine powered by a huge steam engine. speed. (Herman Hollerith)Tabulating machine-the tabulating machine is capable of reading data, processing it and giving the desired ENIAC - **Definition**: Electronic Numerical Integrator and Calculator - **Designers**: John W. Mauchly and John Presper Eckert. **UNIVAC** - **Definition**: [Universal Automatic Computer] - **Designers**: John W. Mauchly and John Presper Eckert. **FIRST GENERATION OF COMPUTERS** - **Time Period**: Developed during 1941 to 1956. - **Characteristics**: - Very large and expensive. - Used vacuum tubes and magnetic drums. **SECOND GENERATION OF COMPUTERS** - **Time Period**: Developed during 1956 to 1963. **THIRD GENERATION OF COMPUTERS** - **Time Period**: From 1964 to 1971. - **Examples**: IBM 1130, UNIVAC 1107. **FOURTH GENERATION OF COMPUTERS** - **Time Period**: Not explicitly stated, but follows the third generation. - **Characteristics**: - Development of mouse and joysticks. - Ability to interlink computers in a network. **FIFTH GENERATION OF COMPUTERS** - **Time Period**: Began in the 1980s and is still evolving today. - **Characteristics**: Represents the latest phase of computer development. #### Data Transmission - Data is transferred to and from a computer as electrical signals (on or off). - To process data (text, images, sounds), the computer converts information into binary form. #### Binary Number System - **Definition**: A base-2 number system with values of either 0 or 1. #### Bits and Bytes - **Bit**: Each 0 or 1 in the binary system; short for "binary digit." - **Byte**: A group of 8 bits that represents one character, digit, or other value. ### Types of Switches in Computers - **Transistors**: Electrical switches made from semiconductor material. - **Integrated Circuits (Chips)**: Tiny regions of semiconductor material that support numerous transistors. ### Types of Computers - **Basic Designs**: (1) Portable and (2) Stationary. - **Portable Computers Categories**: 1. Cell phones 2. Tablets 3. Laptops ### Cellphones - Components: Processor, memory, input and output devices. - Requires its own OS software and applications. ### Features of Smartphones - Internet access - Personal information management (PIM) features - Voice recording - Music file management - GPS services - Digital image and video capture - Computing power for programs (e.g., word processors) ### Tablets - Similar to smartphones in features and operating systems (iOS, Android, Windows). - Touch-screen interfaces and long battery life. ### Laptop or Notebook Computers - Definition: A portable computer with a keyboard, monitor, and other devices in one compact case. - **Choosing a Portable Device**: Consider power, screen size, battery life, weight, and device count. ### Variations of Laptops 1. **2-in-1 PCs**: Convert between laptop and tablet modes. 2. **Ultrabooks**: Thin, lightweight computers (e.g., MacBook Air, Asus ZenBook). 3. **Chromebooks**: Use Google Chrome OS, primarily cloud-based storage. ### Guidelines for Choosing a Portable Device - Battery life - Weight vs. cost - Number of devices available ### Stationary Computers #### Advantages of Desktop Computers - Easier to upgrade - Larger screens beneficial for work ### Other Types of Computers - Mainframe - Supercomputer - Embedded computer ### Input and Output Devices - **Input Devices**: Various methods to input data into a computer. - **Output Devices**: Sends processed data out of the computer (text, graphics, audio, video). ### Types of Output Devices - **Display Screens**: LCD, LED, OLED. - **Audio Output**: Integrated speakers, headphones. - **Printers**: Inkjet and laser printers. ### The Motherboard and Memory - **Motherboard**: Main circuit board of the system. - **RAM**: Temporarily holds software instructions and data; volatile. - **ROM**: Holds startup instructions; permanent. ### Central Processing Unit (CPU) - **CPU:** The \"brains\" of the computer, controls functions and processes commands. - **Processor Speed**: Measured in hertz (Hz), cycles per second. ### Storing Data and Information #### Local Storage Devices - **Hard Drive**: Primary permanent storage device (nonvolatile). #### Portable Storage Options - External hard drives, flash drives, Micro SD. #### Cloud Storage - Files stored on the Internet rather than solely on a device. ### Connecting Peripherals to the Computer - **Computer Ports**: Thunderbolt, USB, Ethernet, HDMI. **System Software** **Definition** - **System Software**: A group of programs that control how a computer functions. **Primary Types of System Software** 1. **Operating System** 2. **Utility Programs** **Primary Functions of an Operating System** 1. **Managing Hardware**: Includes the processor, memory, storage devices, and peripheral devices (e.g., printer). 2. **Managing Software**: Allows application software to work with the central processing unit (CPU). 3. **Managing Tasks**: Involves scheduling and coordinating processes (like reading keyboard strokes) and managing network resources. **User Interface** - Interact with your OS through the **User Interface**: The desktop, icons, and menus that let you communicate with your computer. **Operating Systems for Personal Use** - Tailored for personal computers. **Operating Systems for Machinery, Networks, and Business** - **Real-Time OS (RTOS)**: Performs repetitive specific tasks in precise time. - **Multiuser Operating System**: Also known as **network OS,** allows multiple users to access the computer simultaneously (e.g., UNIX). **Operating System Functions** - Coordinates and directs the flow of data and information. **Types of User Interfaces** - **Command-Driven Interface** - **Menu-Driven Interface** - **Graphical User Interface (GUI)** **Functions of the Operating System** 1. **Hardware Coordination**: - Event management - Interrupt handler - Preemptive multitasking - Spooler 2. **Memory and Storage Management**: - RAM has limited capacity. - Borrowing drive space is called virtual memory. - Increase RAM to avoid using virtual memory. - Concepts: Swap file, paging, and trashing. 3. **Software Application Coordination**: - Blocks of code the CPU recognizes for similar procedures. - Example: Microsoft DirectX and Application Programming Interface (API). **Starting Your Computer** **The Boot Process** 1. **Activating BIOS**: Manages data exchange between the OS and input/output devices; loads OS into RAM. 2. **Performing Power-On Self-Test**: Ensures essential peripheral devices are operational. 3. **Loading the OS**: System files and kernel (essential OS component) are loaded into RAM. 4. **Checking Configurations and Customizations**: Registry contains configurations used by the OS and applications. **Windows Interface** - **Desktop**: Primary working area. - **Taskbar**: Displays open and favorite applications for easy access. - **Start Menu**: Provides access to all applications installed on the device. **User Interfaces for Other OSs** - **macOS and Windows**: Similar in functionality. - **Linux**: Most interfaces are based on familiar Windows and macOS paradigms. **File Management** **Organizing Your Files** - **Directory**: Hierarchical structures of computer content, including drives, libraries, folders, subfolders, files, and root directory (C:). - **File**: Collection of program instructions or data treated as a single unit and stored on a permanent storage device. - **Folder**: Collection of files. **File Path Conventions** - **Windows**: Backslash \\ - **Linux**: Forward slash / - **macOS**: Colon : **File Explorer** - Main tool for finding, viewing, and managing computer contents; shows the location and contents of every drive, folder, and file. **Managing Files** - **Copying, Moving, and Deleting Files**: - Open, Copy, Cut, Rename, Delete, Recycle Bin. **File Compression Utility** - Makes large files more compact, easier, and faster to send. Built-in file compression available. **Windows Administrative Utilities** - **Utility Programs**: Incorporated into the OS (firewall, file-compression utilities) and standalone programs (antivirus, security programs, freeware). **System Performance Utilities** - **Disk Cleanup** - **Task Manager** - **Disk Defragmenter** **File and System Backup Utilities** - **File History** - **System Restore** **Accessibility Utilities** - Designed for users with special needs. **Input and Output Hardware** **Input Hardware** - **Definition**: Devices that convert data into a form the computer can process (like translating words, numbers, sounds, and pictures into binary code). - **Types**: 1. **Keyboards**: Converts letters, numbers, and characters into electrical signals. - **How it works**: - Pressing a key interrupts the current flow in circuits. - The processor identifies the break and matches it with the character map. - The character is sent to the computer as a data stream. - **Types of Keyboards**: - Standard (104-108 keys) and laptop keyboards (80-85 keys). - Wired (USB) and wireless (Bluetooth, RF). 2. **Pointing Devices**: Control the cursor on the screen. - **Examples**: - **Mouse**: Can be mechanical or optical. - **Trackball**: A ball on a stationary device. - **Touchpad**: A flat surface for finger control. - **Touch Screen**: Responds to touch, used in ATMs and smartphones. - **Light Pen and Digitizer**: Used for drawing and graphics. 3. **Source Data-Entry Devices**: Input data directly into the computer without using a keyboard. - **Examples**: - **Scanners**: Convert images and text into digital form. - **Bar-Code Readers**: Translate barcodes into digital codes. - **RFID**: Uses tags to identify items. **Output Hardware** - **Definition**: Devices that convert processed information from the computer into a form humans can understand (like displaying information or printing it). - **Types**: 1. **Softcopy Output**: Electronic display (e.g., on screens). It is not tangible. 2. **Hardcopy Output**: Tangible output (e.g., printed documents). - **Display Devices**: 1. **Types of Screens**: LCD, Plasma, CRT (less common now). 2. **Resolution**: Measured in dots per inch (dpi); higher dpi means clearer images. - **Printers**: 3. **Types**: - **Laser Printers**: High-quality and fast. - **Inkjet Printers**: Use ink droplets to create images. - **Multi-function Printers**: Combine printing, scanning, copying, and faxing. - **Audio and Video Output**: 4. **Sound Output**: Requires sound cards and good speakers. 5. **Voice Output**: Converts digital data to speech. 6. **Video Output**: Produces moving images; requires powerful hardware. **Future Trends** - More diverse input and output methods are expected, including improved technology for people with disabilities and advancements in speech recognition and biometric devices.