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Abstractions & PracticalitiesApril 20th, 2004

The Man Behind the Machine

• Howard Hathaway Aiken

• Born: March 9th, 1900• Died: March 17th, 1973• Harvard graduate

student in Theoretical Physics

• Inventor of the Harvard Mark Series

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

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.

                                                  

                                                                                  

 

Unloading the ASCC outside of Harvard

Specifications

• The Harvard Mark I was capable of 5 operations:

• addition• subtraction• multiplication• division• reference to last

results

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.

                                         

                                                                                           

 

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.

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.

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

Sources

• The IBM Archiveshttp://www-1.ibm.com/ibm/history/exhibits/markI/markI_intro.html

• Aiken’s Biographyhttp://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Aiken.html