CS 1150 - Chapter 1 Textbook Notes

1.1 Introduction 

  • Programming = to create (or develop) software, which is called a program 
  • Software contains instructions that tell a computer or computerized device – what to do 
  • Software plays a huge role in running: 
    • Airplanes 
    • Cars 
    • Toasters 
  • Examples of Software: 
    • Word processors to write documents  
    • Web browsers to explore the Internet 
    • Email programs to send and receive messages 
  • Software developers creates software with the help – of powerful tools called program languages 

1.2 What is a Computer 

  • A computer both includes hardware and software 
    •  Hardware = comprises the visible and physical elements of the computer 
    • Software = is invisible instructions that control the hardware and make it preform specific tasks 
  • A computer consists of the following major hardware components 
    • CPU = Central Processor Unit 
    • Memory = Main memory 
    • Storage Devices 
    • Tapes 
    • Disk 
    • CDs 
    • Input Devices 
    • Mouse  
    • Keyboard 
    • Output Devices 
    • Monitor 
    • Printers 
    • Communication Devices 
    • Modems 
    • NIC = Network Interface Cards 
  • Bus = A computers components that are interconnected by the subsystem 
    • You can think of a Bus like a system of roads that are along the computers components 
    • Data and power go along the bus that will go from one side of the computer to the other  
  • Bus is built into the computer's motherboard, which is a circuit case that connects all of the parts of a computer 
  • Bus is a communication system that transfers data between the components inside a computer 

1.2.1 Central Processing Unit 

  • CPU is the computer's brain 
  • Retrieves instructions from memory and executes them  
  • 2 Components: 
    • Control Unit 
    • Controls and Coordinates the actions of other components 
    • Arithmetic/ log Unit 
    • Performs numeric operations 
      • Addition  
      • Multiplication 
      • Division 
      • Subtraction 
    • Logical operators for comparisons 
  • CPU are built on small tiny semiconductor chips that contains millions of electric switches, that are called transistors which is processor information.  
  • Every computer has an internal clock that emits electronic pulses at a constant rate 
    • A higher clocks speed enables more instructions to be executed in a given period of time 
    • A unit of measurement for a clock is 1 hertz which is equal to 1 pulse per second.  
    • Today's clock speed of hertz is in gigahertz which is about 1 billion pulses per second 
  • Core = A part of processors that performs reading and executing instructions 
  • To increase CPU processing power, you can use one that contains multiple cores. 
  • A multi core CPU is a single component with two or more independent cores.  

1.2.2 Bits and Bytes: 

  • A computer is series of switches 
    • When the switch turns on, it sends a one and when the switch turns off, then it sends out a 0. 
    • These 0's and 1's are interpreted as digits in a binary number system 
    • That is called bites 
  • The minimum storage unit in a computer is called a byte 
  • Byte = contains 8 bytes 
  • To a store a number that cannot fit into a single byte, a computer will use separate bytes 
  • Data are encoded as series of bytes 
    • Those would be numbers and characters 
  • The computer system will automatically, based on the encoding scheme 
  • Encoding scheme = A set of govern rules that tells the computer how to translates numbers and characters into data with which the computer can actually work 
  • A computer storage capacity is measured in byte and multiple of bytes 
    • Kilobytes = about 1,000 bytes 
    • Megabytes = about 1 million bytes 
    • Gigabytes = about 1 billion bytes 
    • Terabytes = about 3 trillion bytes