1. & Abstractions & Practicalities April 20 th, 2004

2. The Man Behind the Machine Howard Hathaway Aiken Born: March 9 th, 1900 Died: March 17 th, 1973 Harvard graduate student in Theoretical Physics Inventor of the Harvard Mark Series

3. The ASCC The Automatic Sequence-Controlled Calculator, also known as the Harvard Mark I The first electromagnetic digital calculator in the United States. 51 Feet 8 Feet

4. Developement Aiken proposed the idea for an automatic calculator in the 1930’s, first to the Harvard Physics Department, then to the Monroe Calculating Machine Company, and eventually to IBM. IBM was impressed with the idea and set some of their best engineers to aid Aiken at the IBM research lab. Although slowed by wartime issues, the machine was unveiled to Harvard in 1944.

5. Unloading the ASCC outside of Harvard

6. Specifications The Harvard Mark I was capable of 5 operations: addition subtraction multiplication division reference to last results

7. Mathematical Problems Addressed by the ASCC computation and tabulation of functions evaluation of integrals solution of ordinary differential equations solution of simultaneous linear algebraic equations harmonic analysis statistical analysis.

9. Specifications (cont.) Fed a sequence of instructions via punch-cards The ASCC could computer to 23 significant figures A single addition took about 6 seconds Division took 12 seconds.

10. Even More Specifications You could also provide input through hundreds of manually-set switches This machine was used to calculate repetitive data tables for the military during the war.

11. The SSEC The Selective Sequence Electronic Calculator was the successor of the ASCC Build by Aiken in 1948 Was more than 250 times faster than the ASCC

12. Sources The IBM Archives http://www-1.ibm.com/ibm/history/exhibits/markI/markI_intro.html Aiken’s Biography http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Aiken.html