CSC121 TOPIC 1

• Computer


  An electronic device, operating under the control of instructions stored in its own memory, that can accept data, process the data according to specified rules, produce results, and store the results for future use
• Computer


  • Consists of two major components: hardware (electronic devices) and software (instructions/programs)
  • The software is stored in the computer's own memory
• Hardware


  The physical components that make up the computer
• Software


  • Step-by-step instructions that tell the computer how to do its work
  • It's purpose is to convert data to useful information
• Computer components


  • Input device
  • System unit
  • Output device
  • Primary storage
  • Storage device
  • Communication device
• Software types

  • Operating system
  • Utilities
  • General-purposed application software
  • Specialized application software
  • Apps
• People are using computers everywhere: at work, at school, and at home
• Computers technology changes rapidly, and users must keep up with the changes to remain digitally literate
• Computer literacy or Digital literacy

  Involves having a current knowledge and understanding of computers, mobile devices, the web, and related technologies
• A computer receives data, processes, produce output, and store information
• Input device


  Allows you to enter data and instructions into a computer
• Output device


  Hardware component that conveys information to one or more people
• System unit


  The case that contains the electronic components of the computer that are used to process data
• Storage device


  Records (writes) and/or retrieves (reads) items to and from storage media
• Communications device


  Enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices
• System software


  • Provides an environment for user to execute the application software
  • Enables the application software to interact with computer hardware
• Application software


  • End user software
  • A program that performs a common task to the user
• A network is a collection of computers and devices connected together, often wirelessly, via communications devices and transmission media
• The Internet is a worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals
• Types of computers


  • Personal computers
  • Mainframe computers
  • Midrange computers
  • Supercomputers
• Personal computers


  Can perform all of its input, processing, output, and storage activities by itself
• Types of personal computers

  • Desktops
  • Laptops
  • Tablets
  • Smartphones
  • Wearables
• Mainframe computers


  Large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously
• Midrange computers


  Computers with processing capabilities less powerful than a mainframe computer yet more powerful than a personal computer
• Supercomputers


  The fastest, most powerful computer and capable of processing more than one quadrillion instructions in a single second
• John Von Neumann proposed Von Neumann Architecture
• Von Neumann Architecture


  • Data & instructions are both stored in main memory while being processed
  • Sequential processing of instructions
  • Binary data processing
  • Consists of CPU, memory, & I/O system
• Central Processing Unit (CPU)


  Contains the control unit (CU), arithmetic/logic unit (ALU) and Interface unit
• ALU


  Performs arithmetic and Boolean logical calculations
• CU


  • Controls processing of instructions
  • Controls movement of data within the CPU
• Interface unit


  Moves instructions and data between the CPU and other hardware components
• Bus

  Bundle of wires that carry signals and power between different components
• Analog data


  Continuous and take continuous values
• Digital data


  Have discrete states and take discrete values
• Digital electronic signals are in one of two states: on(1) or off(0) and are recognized by computers
• Analog signals are continuous
• Data


  Can be analog or digital
• Analog data


  • Sounds made by a human voice
• Digital data


  • Data stored in computer memory in the form of 0s and 1s
• Analog to digital conversion

  1. ADC converts analog data to signal

  2. DAC converts digital data to analog