History of Computing

• Abacus
  • Record number values
• Important people
  • Blaise Pascal
  • Joseph Jacquard
  • Charles Babbage
  • Ada Lovelace
  • Alan Turing
• Harvard Mark I, ENIAC, UNIVAC I
  • Early computers
  • Launched new era of maths, physics, engineering, and economics

Hardware

First Generation Hardware (1951-1959)

• Vacuum tubes
  • Large
  • Not reliable
  • Lots of heat
• Magnetic drum
  • Memory device that rotated under read/write head
  • When memory cell was under head, data could be read/written
  • Very manual
• Card readers --> magnetic tape drives
  • Card readers that read holes punched in a card
  • Sequential auxiliary storage devices
  • Audio cassettes

Second Generation Hardware (1959-1965)

• Transistor
  • Replaced vacuum tube
  • Fast, small, durable, cheap
  • Nobel prize was rewarded for invention
• Magnetic cores
  • Replaced magnetic drums
  • Information is available instantly
  • CPU no longer has to wait for drum to get to proper place to read/write
• Magnetic disks
  • Replaced magnetic tape
  • Data accessed directly
  • Faster because you can refer to location of data

Third Generation Hardware (1965-1971)

• Integrated circuits
  • Replaced circuit boards
  • Smaller, cheaper, faster, more reliable
  • Solid silicon containing transistors and other components
  • Boards were printed
• Transistors
  • Now used for memory construction
  • One transistor = one bit of information
• Terminal
  • Input/output device with keyboard and screen
  • Direct access to computer + immediate response

Fourth Generation Hardware (1971-Present)

• Large-scale integration (LSI)
  • Great advances in chip tech
• PCs, commercial market, workstations
  • Computers become affordable
  • Huge companies like Apple, Sun, Dell, etc.
• Laptops, tablets, and smart phones
  • A computer in everyone's hands
• Parallel computing
• Networking
  • Ethernet used to connect computers
  • Resources can be shared over the network
• Cloud computing
  • Use of computer resources on the Internet

Software

First Generation Software (1951-1959)

• Machine language
  • Computer programs written in binary
• Assembly languages and translators
  • Programs written using mnemonics
  • Mnemonics get translated to machine code
• Programmers split into two groups
  • Application programmers
  • Systems programmers

Second Generation Software (1959-1956)

• High level programming languages
  • Made programming easier
  • FORTRAN, COBOL, Lisp

Third Generation Software (1965-1971)

• Systems software
  • Humans were too slow
  • Put computer resources under control of the computer
    • Operating systems decide what to run and when
• Separation between users and hardware
  • Software is being written for general public

Fourth Generation Software (1971–1989)

• Structured programming
  • Pascal
  • C++ (cpp)
• New application software for users
  • Spreadsheets
  • Word processors
  • DBMS

Fifth Generation Software (1990-Present)

• Microsoft dominates the market
• OOP (object oriented programming)
  • Hierarchy of data objects
  • Java, etc.
• World Wide Web
• New users
  • Don't need computer knowledge to benefit

Computing as a Discipline

• What can be efficiently automated?
  • Four necessary skills:
    • Algorithmic thinking
      • Express problems in terms of step-by-step procedures
    • Representation
      • Store data in a way it can be process efficiently
    • Programming
      • Algorithmic thinking + Representation --> computer software
    • Design
      • Software that serves a purpose

Computer Science History