Content of this lecture
• The dark age (1945 – 55): no OS
• Batch systems (1955 – 65)
• Multiprogramming (1965 – 80)
• PC (and mobile) era (1980 – present)
The dark age
• ENIAC (1946): the first computer
• Only a single group of people designed and used it
Batch systems (1955-65)
• Background:
• At that time, computers are used only to “compute” (instead
of entertainments, etc.)
• Users write program using “punch card”
• Punch your program into cards
• Bring the cards to computer operators
• Come back after a day to get result
• Protection and virtualization are not needed!
• How to Allocate and Reclaim computation time?
• Sign-up sheet on the wall!