Arnold Neustadter

Arnold Neustadter (25 August 1910 – 17 April 1996)^[1] was an American inventor and businessman. He invented the Rolodex desktop rotating card file and other office equipment with Danish engineer Hildaur Neilson,^[2] which has been called "a triumph of low technology"^[3] and "a lasting symbol of the art of networking".^[1]

Neustadter's earlier inventions included the Autodex, a spring-operated phone directory that automatically opened to the selected letter, Swivodex, an inkwell that did not spill, Punchodex, a paper hole puncher, and Clipodex, a transcription aid that attached to a stenographer's knee.^[4]