1950s

• ENIAC: First computer
  • No OS
  • App controls resources

  

  Reference: https://ko.wikipedia.org/wiki/%EC%97%90%EB%8B%88%EC%95%85

Early 1960s

• Increasing users and programs
  • First OS using Batch Processing System
    • Execute program in consecutive order
  • Cons of batch processing system
    • Long response time (if slow program run first)
    • Long execution time (App can occupy CPU when it does not need it)

  

Late 1960s

• New systems proposed - Not yet implemented in OS
  • Time Sharing System - Divide CPU usage time
    • Support multi user
    • Minimize computer response time

  

  • Multi Tasking
    • Creating an illusion of simultaneous program execution to user in single CPU (like a flip book)
    • Usually multi tasking = time sharing system
  • Multi Programming
    • Maximize CPU Utility (CPU usage per time)

  

• Summary
  • Divide time to execute multiple program
    • Shorter response time (Time sharing system, support multi user)
    • Shorter execution time (Multi programming)
    • User feels multiple program runs simultaneously (Multi tasking)

1970s

• UNIX OS: Actual OS came out
  • C Language by Dennis Ritchie
  • Multitasking, Time sharing system, Multiprogramming
  • Single computer used by multiple users
• Why need C language?
  • Assembly language was used to develop S/W before 1970
    • Every computer needed to be re-programmed due to each computer’s different H/W (CPU, Memory,…)
    • High complexity in programming
  • C language in 1970s
    • Compiler: no need for re-programming
    • Low complexity in programming

1980s

• Personal Computer (PC)
  • Don’t need to share single computer
• UI
  • CLI: Keyboard (until early 1980)
  • GUI: Mouse (mid 1980)

1990s

• Era of application program by GUI environment
  • Excel, PPT, etc
  • Popularization of Windows
• Network technology
  • Popularization of www internet
• Open source campaigne (open and free for everyone)
  • Linux OS

after 2000

• Vitalization of open source
  • Linux
  • Apache
  • MySQL
  • Android
  • Deep Learning
  • IoT …
• Virtual machine
  • Single CPU runs multiple OS
• Massive parallel computing