Computer Characteristics

Computer Characteristics

• Computers are essential tools for various applications, with multiple characteristics.
• Modern computers can execute billions of instructions per second.
• Computer speed is measured in Megahertz (MHz).
• Computers store vast data amounts, which can be retrieved quickly.
• Primary computer memory is limited.
• Secondary storage devices like disks allow larger data storage.
• The accuracy of computers is high when tasks are based on correct instructions.
• Faulty input can result in errors, but the machines themselves are precise.
• Computers operate consistently under defined standards without failure, ensuring reliability over time.
• Once programmed, computers automate tasks without human intervention, controlling attached devices automatically.
• Computers do not suffer from fatigue, which enables continuous operation with consistent accuracy.
• Modern computers are versatile and handle tasks such as playing games, sending emails, and creating presentations.
• Flexible software enables versatility.
• Computers enable seamless communication and data exchange via networks and the internet due to connectivity.

Computer Generations

• The evolution of computers is divided into five generations.
• First Generation (1940s–1950s) used vacuum tubes for circuitry and magnetic drums for memory.
• First-generation operated on binary machine language.
• First-generation computers were large, expensive, and energy-intensive with ENIAC as an example.
• Second Generation (1950s–1960s) replaced vacuum tubes with transistors, making computers smaller and faster.
• Second-generation used assembly language and magnetic core memory with IBM 1401 as an example.
• Third Generation (1960s–1970s) introduced integrated circuits, which significantly reduced size and cost.
• Third-generation supported high-level programming languages like FORTRAN, and IBM System/360 was an example.
• Fourth Generation (1970s–1980s)'s Microprocessors integrated millions of transistors into a single chip.
• Fourth-generation Personal computers became widespread, and the IBM PC was an example.
• Fifth Generation (1980s–Present) focuses on artificial intelligence and parallel processing.
• Fifth generation uses natural language processing and machine learning with Al-based supercomputers as an example.

Computer Applications

• Computers are utilized in various fields.
• Communication: Emails, instant messaging, and video conferencing facilitate instant global communication.
• Entertainment: Used for gaming, watching movies, and creating special effects in films.
• Banking simplifies transactions, maintains records, and enables ATMs for easy cash withdrawal.
• Education enhances learning through e-books, online courses, and virtual classrooms.
• Healthcare: Used in managing patient records, medical imaging, and telemedicine.
• Engineering assists in design and simulations using CAD software.
• Science facilitates research, data analysis, and weather forecasting.
• E-commerce supports online shopping and payment systems.

Computer Architecture

• The computer architecture comprises the following units: Input Unit, Central Processing Unit (CPU), and Output Unit.
• Input Unit: Devices like keyboards and mice are used to feed data into the computer.
• Central Processing Unit (CPU) directs the operations of the system via the Control Unit.
• The Arithmetic and Logic Unit (ALU) in the CPU performs arithmetic and logical operations.
• The CPU's Main Memory (MM) Temporarily stores data and instructions.
• Output Unit: Devices like monitors and printers present the processed data to the user.
• Data flows Via the input unit, data is processed in the CPU and presented through the output unit.
• The control unit manages the entire process, ensuring proper instruction execution.

Computer Types

• Microcomputers are the smallest and most common computers.
• Microcomputers are used in homes, schools, and offices.
• Examples of microcomputers include laptops, and desktops.
• Minicomputers are medium-sized computers used in research and business and support multiple users simultaneously.
• An example of a minicomputer is the PDP-11.
• Mainframe Computers are large, powerful systems used by organizations for bulk data processing.
• An example of a mainframe computer is the IBM Z-series.
• Supercomputers are the fastest computers designed for complex simulations and scientific computations.
• An example of a supercomputer is the Cray XC50.

Number Systems

• Number systems can be broadly categorized into positional and non-positional systems.
• These systems differ in terms of digit value representation and arithmetic complexity.

Non-Positional Number System

• In Non-Positional Number Systems, each symbol has a fixed value, regardless of its position in the number.
• Non-Positional Number Systems' symbols represent values directly, cannot represent zero, and arithmetic like addition/multiplication is challenging.
• The Roman numeral system is an example where "X" equals 10 and "C" equals 100, regardless of position.

Positional Number System

• In Positional Number System, the value of a digit depends on the number and the base (or radix) of the system.
• Positional Number Systems includes systems like binary, decimal, octal, and hexadecimal. Arithmetic operations are straightforward.
• An example of a positional system is the decimal system, the number 325 means (3 x 10²) + (2 x 10¹) + (5 x 10°).
• Positional Number Systems are more versatile and widely used in computing and mathematics compared to non-positional systems.

Number Systems Types

• Number systems define how numbers are represented.

Decimal Number System

• Decimal Number System base is 10, uses digits 0-9, and it is commonly used in daily life.
• Example: 345 in base 10 is (3 x 10²) + (4×10¹) + (5 × 10⁰).

Binary Number System

• Binary Number System base is 2, uses digits 0 and 1, and is used in computers and digital systems.
• The Binary Number System is easy for hardware to represent ON (1) and OFF (0) states.
• Example: Binary representation of 8 is 1000₂.

Octal Number System

• Octal Number System base is 8, uses digits 0-7, and and is used in computing to simplify binary representation.
• Decimal number 359 is represented as 547₈.

Hexadecimal Number System

• Hexadecimal Number System's base is 16, with digits 0-9, A–F (where A=10, B=11,..., F=15).
• Hexadecimal Number System simplifies binary representation for programmers.
• The Hexadecimal Number System is commonly used in memory addresses.
• Example: Decimal number 255 is represented as FF₁₆.

Number System Conversion

• To convert 75₁₀ into various systems:

Binary Conversion

• Repeated division by 2, noting remainders must be used.
• Write remainders in reverse: 75₁₀=1001011₂.
• 75÷2= 37 remainder 1, 37÷2= 18 remainder 1, 18÷2=9 remainder 0, and 9÷2=4 remainder 1.
• also 4÷2=2 remainder 0, 2÷2=1 remainder 0, and 1÷2=0 remainder 1

Octal Conversion

• Repeated division by 8 must be used.
• Write remainders in reverse: 75₁₀=113₈.
• 75÷8=9 remainder 3, 9÷8=1 remainder 1, and 1÷8=0 remainder 1

Hexadecimal Conversion

• Repeated division by 16 must be used.
• Write remainders in reverse: 75₁₀=4B₁₆.
• 75÷16=4 remainder 11 (B in hexadecimal) and 4÷16= 0 remainder 4

Decimal Equivalents

• To convert 55₈ to Decimal you have to use positional values of base 8:
• (55)₈=(5×8¹)+(5×8⁰), 40+5=45₁₀
• To Convert (78.12)₁₆ to Decimal it must be split into integer and fractional parts.
• Integer part: (78)₁₆=(7×16¹)+(8×16⁰)=112+8=120
• Fractional part: (0.12)₁₆=(1×16⁻¹)+(2×16⁻²)=0.0625+0.0078125=0.0703125 Combine: (78.12)₁₆=120+0.0703125=120.0703125₁₀

Binary to Hexadecimal Conversions

• To convert binary (110101011)₂ to hexadecimal follow following steps:
• Group Binary Digits in 4-Bit Sections (from right to left): 110101011 → 0001 1010 1011 (add leading zeros).
• Convert Each Group to Hexadecimal: 0001=1, 1010=A, 1011=B.
• Combine the Results: (110101011)₂=(1AB)₁₆

Memory

• Memory devices are essential computer components are classified the following ways:

Primary Memory

• Primary Memory is for temporary data and instructions, directly accessible by the CPU.
• RAM is Random Access Memory that is Volatile for temporary storage during processing.
• SRAM (Static RAM) is faster.
• DRAM (Dynamic RAM) requires refreshing but is cost-effective.
• ROM (Read-Only Memory) is Non-volatile for permanent storage of essential instructions.
• EPROM (Erasable Programmable ROM) Can be erased using UV light and reprogrammed.
• EEPROM (Electrically Erasable PROM) Allows electrical erasing and rewriting without removing the chip.

Secondary Memory

• Secondary Memory is Non-volatile and used for long-term storage.
• Hard Drives are Used for bulk data storage, an example is SATA HDD.
• Flash Drives are Portable, reliable, and compact.

Peripheral Devices

• Peripheral devices expand a computer's functionality.

Input Devices

• Input Devices captures user data and sends it to the system.
• Examples include: Keyboard, Mouse, and Scanners.
• Keyboards are the primary input for text and commands.
• Mice are a pointing device for GUI navigation.
• Scanners converts physical documents into digital format.

Output Devices

• Output devices display or convey processed data to users.
• Monitors (VDU) display visuals in technologies like CRT and LCD.
• Printers converts digital content into physical form.

Storage Devices

• Storage devices store data for immediate or future use.
• Hard Drives provide Long-term data storage.
• Flash Drives are portable.

Plasma Technology

• Plasma technology uses the excitation of gases to produce visuals.
• A gas mixture of neon and other gases fill the gap between two glass plates.
• Conductive Ribbons include Horizontal on one plate and vertical ribbons on another plate.
• To apply, a voltage must be applied to intersecting ribbons.
• This ionizes gas molecules and creates glowing plasma, with each forming a pixel on the screen.
• Plasma displays provide high-quality visuals suitable for large-format screens like TVs.

Language Processors

• Language processors convert human-written programs into machine-understandable code.
• High-level Language provides Programming languages like Java or C that are easier for humans but need translation into machine language (binary) for execution.
• Types of Language Processors
  • Compilers converts the entire program into machine code in one step.
  • Interpreters translate and executes code line by line.
  • Assemblers converts assembly-level instructions into machine code.

Cathode Ray Tube

• Cathode Ray Tube (CRT) is an older display technology that uses electron beams to produce images on a phosphor-coated screen.
• An electron gun Emits electrons, directed toward the screen.
• The screen is coated with phosphor dots, which form images.
• Each pixel consists of three phosphor dots (Red, Green, Blue). Using varying electron intensities creates different colors.

Windows Operating Systems.

• User Interface:
  • Windows XP introduced a simplified interface with a taskbar and Start Menu for easier navigation.
  • Windows 10 combines the traditional Start Menu with live tiles and supports touchscreens.
• Performance:
  • Windows XP is optimized for 128 MB RAM minimum.
  • Windows 10 requires higher specifications (2 GB RAM minimum for 64-bit systems).
• Security:
  • Windows XP is Vulnerable with outdated security protocols and lacks official support since 2014.
  • Windows 10 Features advanced security like Windows Defender, regular updates, and biometrics with Windows Hello.
• Features:
  • Windows XP offers Limited to basic functionality with features like Internet Explorer 6 and simple media playback.
  • Windows 10 includes Cortana, Edge browser, and seamless integration with cloud services like OneDrive.
• Compatibility:
  • Windows XP. is Compatible with older hardware and software but lacks support for modern applications.
  • Windows 10 supports legacy applications via compatibility modes.

Windows Activation

• The Activation Process ensures a genuine and licensed copy of Windows linking a product key to a device.
• Purpose of Activation:
  • To verify authenticity, prevent piracy and enable access to features and updates.
• Steps:
  • Step 1: Obtain a product key.
  • Step 2: Enter the key during installation or via settings.
  • Step 3: Connect to the internet to verify the key with Microsoft servers.
• Types:
  • Digital License automatically links to a device.
  • Product Key Activation Requires manual entry of a 25-character key. Without activation, Windows operates in a limited state with restricted customization and updates.

User Profiles

• A User Profile contains personalized settings and data for a user, such as desktop setup, documents, and application configurations.
• To create you must Go to Control Panel > User Accounts.
• Select Add a new user.
• Roaming User Profiles offer portability across a network through central storage; mandatory profiles restrict modification of the defaults.
• User profiles include settings, functionality, usage, and examples.

Windows Account Types

• Account types in Windows include settings, features, and examples. Microsoft support multiple account types.

Administrator Accounts

• Administrator Accounts offer full system access.
• Users can install software, and configure settings with examples like IT staff in an organization.

Standard User Accounts

• Standard User Accounts provide Limited access but users can use applications, example is home users or children.

Guest Accounts

• Guest Accounts are Temporary with Restrictions on installed programs or personalized settings.

Child Accounts

• Child Accounts have parental controls with activity monitors and enforcement of screen-time limits.

User Access Security

• User accounts enable individuals to log in with personalized settings and permissions.
• Creation: Administrator accounts manages security via Settings > Accounts > Family & Other Users
• Features: use Password Protection, Two-Factor Authentication, user Permissions, and Encryption. Examples: Standard User Account protects against installing malware; Administrator Account recovers data or modifies settings.

MS Word Customization

• Customizing a Word document enhances its usability and layout including the Office Button, Quick Access Toolbar (QAT), Ribbon, themes and styles, and page layout.
• The Office Button's Access options are creating, opening, saving, and printing documents
• The Office Button location is Top-left corner of the window. The QAT contains shortcuts for frequently used commands.
• To customize you must Select "More Commands” to add or remove items like Save, Undo, and Print clicking the drop-down arrow on the QAT and select
• With Ribbon Customization you Modify the arrangement of tabs and groups.
• Steps: Go to File > Options > Customize Ribbon.
• For themes and styles Apply predefined or custom themes to set fonts, colors, and effects via the Design Tab.
• For Layout, adjust margins, orientation, and size under Layout Tab.

Document Layouts

• Print Layout: Displays the document as it will appear when printed. Includes headers, footers, and page breaks via the View Tab.
• Full-Screen Reading is optimized for reading, utilizing the full screen with font size adjustment and tracking changes via the View Tab.
• Web Layout shows how the document will appear as a web page used for creating HTML documents.
• Outline View displays Documents' structure allowing for rearrangement of sections.
• Draft View focuses on text editing by hiding layout elements like images and speeds up navigation in lengthy files.

MS Word Navigation

• Efficient navigation in Word helps users move quickly within documents using a Scroll Bar, Keyboard Shortcuts and Thumbnails, and/or a Document Map.
• Via the Scroll Bar drag and click arrows to scroll
• Keyboard Shortcuts enable to Move by words and paragraphs, and Jump to the beginning or end of a document
• Thumbnails and the Document Map Enable visual navigation through sections.
• With split Screens steps are Go to View Tab > Show > Check Navigation Pane.

Mail Merge

• Mail merge combines a document with a data source to produce personalized letters, labels, or emails.
• To start: Go to Mailings Tab > Start Mail Merge > Step by Step Mail Merge Wizard to Choose Document Type.
• Select recipients using either an existing list, Outlook contacts, or creating a new list.
• Place data fields like name or address under Mailings Tab > Insert Merge Field.
• Preview and then Print personalized documents or email them.

Printing in Word

• Open by clicking the Office Button > Print.
• Select a printer from the dropdown menu and determine the page range options.
• Set the number of Adjust the number of copies to print and Review the document layout using before starting the print command.

MS Excel

• Features include:
  • Data Entry and Storage with numeric and non-numeric data and unique cell references like A1 for storage.
  • Data Sorting and Filtering via alphabetical, numerical, or custom order, displaying only specific data
  • Conditional Formatting highlights data based on conditions. (e.g., =SUM(A1:A10) to add values, =IF(A1>50, "Pass", "Fail") for logical conditions.
  • Creates bar graphs, pie charts, and line charts
  • Data Validation ensures accurate input by number limits or text requirements.

Excel Techniques

• Efficient data management includes data Entry and Storage including Key techniques
  • Select name Box
  • Enter a cell reference to jump directly to that location.
  • Use Go To option.
  • Shortcut: Using CTRL + G or F5 allows jumping to specific cell references or ranges.
  • Keyboard Shortcuts using CTRL + HOME; CTRL + END, and CTRL + Page Up/Page Do
  • For Sheet use arrows at the bottom-left of the workbook and Right-clicking.
  • Use scroll bars to Move vertically and horizontally across large datasets.

Excel Formatting

• Formatting features include:
  • Font and Alignment (Adjust style, size, and color), Number Formatting, and Conditional Formatting. With Row/Column Adjustments, and Borders and Shading
  • Define text data types like numbers, currency, and percentages
  • Currency format has been used to display values and automatically formats cells.

PowerPoint

• PowerPoint is best when you Open > Insert Title Slide > Enter Content > Apply / Design Template > Add Transition > review then Save.
• After launch click on the Office Button and Select the slide layout from the dropdown menu.
• Click in placeholders to add media via the Insert Tab and pre design the template for slides to transition.

Powerpoint Formatting

• Basic formatting in PowerPoint involves adding text, aligning content, changing slide layout, adding images, applying animations, and background customization.
• Using the Font Group in the Home Tab (change font style, size, and color align slides. select the Paragraph Group tab use the animation tabs and design
• Select layouts like Title Slide and Two Content from the Home tab.

Applying powerpoint Template

• PowerPoint design formatting includes pre and creating a custom template
• To apply you most click Apply from the installed templates list an to create, you need To format and style a new side first.

Adding Charts to PowerPoint

• Charts visually represent data:
• To insert use the illustration tab then select a chart or on a new slide click the chart icon fill out excel with new content then select close.

Hard Drives

• Harddrive stores data magnetically on circular disks called platters:
  • Consist of Circular aluminum and glass disks coated with magnetic material divided into sectors written by read/write. positioned over the platters. Operated by a Spindle Motor. The motor rotates the platters. Managed by Actuator Arm
  • Controller Board the computer uses. Each track gets divided into sectors.

CD-ROM Construction

• A CD-ROM (Compact Disc Read-Only Memory) is an optical disc to store digitaal data.
• It includes A Substrate, a reflective layer, with a protective coating that starts at the center and Laser beams read it.

Troubleshoot CD-ROM

• CD-ROM steps are check connections, update the driver, clean the disk, change drive letters, and disable Auto Insert Notification (AIN)
• Navigate to Device Manager > CD-ROM > Settings Tab and uncheck AIN

DVD Features

• DVD features a motorized try for loading disks and an optical lazer
• DVD's have a Decoder function. The is for DECOMPRESSION
• hardware decoders have hardware decoders, analog digital outputs.

Video and troubleshooting

• Set a video with Set resolution to 640x480 with 16-bit.
• Make sure you have updated driver then Check the power supply to and Verify the CMOS Setting in the BIOS. and check for 16 BIT color for compatibility.

Flash Drive Features

• Flashdrives or Flashmemorydrives are portable small memory using nonvolatile data.
• They have compact portability with higher speed and resistant to mechanical damage.

Flash Drive Guideilnes

• Ensure the flash drive is Properly Inserter in USB port to and Update USB or Flasshdrive. Ensure you scan for virus. For more serious issues Reformatting or Try different port.

Input Output devices

• A mouse and trackball a stationary design with customizable buttons.

Key Boards

• KeyBoard matrix detects presses. Keys are coded and are detected when released.
• If cables do not react replace. or Stuck keys Clean.

SOund cards Installation

• SOundcards. Ensure to unplug then Locate an empty PCI or PCIe slot that fits configure jumpers set based on the manual. External divices. Boot into windows is.

IRQ Conflict

• If hardware conflicts. Reassign and move card. Remove then assign settings