Acknowledgements: These slides accompany section 1.2, “Evolving Computer Hardware Affects Programming Languages” of Chapter 1 “Fundamental Concepts” of “Introduction to Functional Programming Using Haskell”.

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First “Modern” Computers

• ENIAC (Electronic Numerical Integrator and Computer) completed 1946

  • cost $500,000 = $7,000,000 today
  • weighed 30 tons, occupied space of small house
  • used 160 kilowatts of electricity
  • had no main memory, 20 accumulators (10 decimal digits)
  • later added 100 words of core
  • used punch cards for external memory
  • were not very reliable
  • designed for military purposes, small perceived market

Computers 70 Years Later (1)

• Processors

  • are much smaller and faster
  • use much less power
  • cost much less money (if mass produced)
  • operate much more reliably
  • are everywhere!

Computers 70 Years Later (2)

• Main memory

  • larger in capacity
  • smaller in physical size
  • faster in access speed
  • less costly
  • less power consumption
  • more reliable

Computers 70 Years Later (3)

• Processors per machine

  • from one to many per machine
  • from one to several per chip
  • from none to several specialized processors
  • trend continues because approach to physical limits

Computers 70 Years Later (4)

• External storage

  • random access
  • larger in capacity
  • smaller in size
  • faster in access time
  • less expensive

Computers 70 Years Later (5)

• Processors per person

  • from one for many people
  • to many computers per person

• Physical presence

  • from isolated in locked rooms
  • to deployed everywhere

Computers 70 Years Later (5)

• Range of applications

  • from a few specialized applications
  • to almost all aspects of human activities

• Cost of human staff to support?

  • probably increased some!

Effects on Practice (1)

• Computers versus humans

  • early computers expensive, human workers relatively inexpensive
  • current computers inexpensive, human workers relatively expensive
  • from optimizing computers to optimizing humans

• Processor time and memory

  • early computer time and memory precious
  • current computer time and memory relatively plentiful
  • THUS: devote significant computing resources to increase human productivity

Effects on Practice (2)

• Problem size

  • early computers for a few small problems (but larger than what easy manually)
  • current computers for many and much larger problems (impossible manually)
  • execution efficiency still important in production
  • THUS: devote significant computing resources to increase programmer productivity and effectiveness

Effects on Practice (3)

• Computers versus applications

  • early days many applications and users share computer
  • currently many computers can support one application or user
  • THUS: use cheap computers to increase productivity and range of application

• Security

  • early computers secure in locked rooms
  • current computers on network with diverse applications and users
  • THUS: security has become thorny issue

Programming Languages

• First using cables and switches

• Machine language

• Assembly language

• High-level languages appeared in mid-1950s

  • First compiler in 1957 (Fortran)

Languages 60 Years Later

• Allocate/deallocate memory automatically rather than manually

• Interpret rather than compiled to machine code

• Exploit multicore systems rather than just one processor

• Incorporate declarative features rather than imperative

  • to optimize programmer productivity
  • to improve reliability and security
  • to better use multicore capabilities