History of Computers
- 1623: Mechanical calculator
- Wilhelm Schickard invented first known mechanical calculator, capable of simple arithmetic.
- Similar mechanical adding machine made in 1640’s by Blaise Pascal. Still on display in Paris.
The "Pascaline," from The History of Computing Project
- 1673: More advanced mechanical calculator
- 1673 by German mathematician Gottfried Leibniz
- Capable of multiplication and division
- Purely mechanical with no source of power.
The "Step Reckoner," from maxmon.com
- 1823: Charles Babbage begins work on Difference Engine
- He designed, but it was completed by a Swedish inventor in 1854.
- Image of the Difference Engine from Niagara College
- 1833: Charles Babbage begins Analytical Engine
- Never completed.
- Important concept: a general-purpose machine capable of performing difference functions based on programming.
- 1834: Ada Byron, Lady Lovelace impressed with the concept of the Analytical Engine at a dinner party.
- Daughter of poet Lord Byran
- Created plans for how the machine could calculate Bernoulli numbers. This is regarded as the first “computer program," and
she is the first "programmer."
- The Department of Defense named a language “Ada” in her honor in 1979.
- 1890: punched cards used by Herman Hollerith to automate Census
- Concept of programming the machine to perform different tasks with punched cards was from Babbage.
- Punch cards based on Josph Marie Jacquard’s device to automate weaving looms.
- Hollerith founded a company that became International Business Machines (IBM) to market the technology.
Sample Punch Card, from About.com
- 1939: prototype of the first electronic computer
- Assembled by John Atansoff and Cliford Barry.
- John Atansoff came up with the concept of using binary numbers.
- Completed in 1942 using 300 vacuum tubes.
- Could solve small systems of linear equations
- Image from The History of Computing Project
- 1946: ENIAC completed
- Electronic Numerical Integrator and Computer
- By Presper Eckert and John Mauchly
- 18,000 vacuum tubes.
- Occupied a 30 by 50 foot room
- Programming by plugging wires into a patch panel. Very difficult to do, because
this style programming requires intimate knowlege of the computer.
ENIAC, from ftp.arl.mil
- 1946: John van Neumann Architecture stored-programming concept
- He suggested that programs and data could be represented in a similar
way and stored in the same internal memory.
- All modern computers store programs in internal memory.
Four generations of computers
- Vacuum tube (1939)
- Transistor (invented in 1947, used in IBM 7090 in 1958)
- Integrated circuit or chip (invented in 1959, used in IBM 360 in 1964)
- A small wafer of silicon that has been photographically imprinted to contain a large number of transistors together.
- Large-scale integration: microprocessor (1975)
- Entire processing unit on a single chip of silicon
Vacuum tube, from computermuseum.li
Robert Noyce, one of the inventors of the integrated circuit and founder of
Intel speaking of a modern computer chip compared to the Eniac: "It is 20 times
faster, has a larger memory, is thousands of times more reliable, consumes the
power of a light bulb rather than that of a locomotive, occupies 1/30,000 the
volume and costs 1/10,000 as much."
Source: Robers, Eric S. The Art and Science of C. Addison-Wesley Publishing Company.