Abacus 4th Century B. C

Howard Aiken

Mark I

Mark I Calculator

1939-1942

• First electronic computer built by John Atanasoff and Clifford Berry
• Computer used binary number system of 1 and 0
• Binary system is still used today

ENIAC - 1946

• Electronic Numerical Integrator And Computer
• a machine that computed at speeds 1,000 times faster than the Mark I was capable of only 2 years earlier.
• Using 18,00-19,000 vacuum tubes, 70,000 resistors and 5 million soldered joints this massive instrument required the output of a small power station to operate it.

ENIAC

ENIAC

1943-1946

• It could do nuclear physics calculations (in two hours) which it would have taken 100 engineers a year to do by hand.
• The system's program could be changed by rewiring a panel.
• Weighed 30 tons and was 1500 square feet (average area of a 3 bedroom house

ENIAC

1946