Rectangular holes punched from cards [was RE: Display-less computing]

[Rich Alderson]

From: Fred Cisin
Sent: Tuesday, December 15, 2015 9:12 AM

> My father claimed that the use of round holes on divergent cards was due 
> to an attempt by IBM to patent the shape of the hole in the cards.

http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/punchcard/

Prior to 1928, the holes in IBM's cards were round, too.  The use of round
holes by Univac was an avoidance of paying royalties to IBM, which held a
patent on 80-column rectangularly punched cards.

                                                                Rich


Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134

mailto:RichA at LivingComputerMuseum.org

http://www.LivingComputerMuseum.org/