Lace card (punched cards)
Lace card

							

						From Wikipedia, the free encyclopedia
					
A lace card from the early 1970s
A lace card is a punched card with all holes punched (also called a whoopee card, ventilator card, flyswatter card, or IBM doily). They were mainly used as practical jokes to cause disruption in card readers. Card readers tended to jam when a lace card was inserted, as the resulting card had insufficient structural integrity to avoid buckling inside the mechanism. Card punchers could also jam trying to produce cards with all holes punched, owing to power-supply problems. When a lace card was fed through the reader, a card knife or card saw (a flat tool used with punched card readers and card punches) was needed to clear the jam.[1][2]


Black fax
Christmas tree packet
Denial of service
List of practical joke topics

This article is based in part on the Jargon File, version 4.2.1, which is in the public domain.


^ "Jargon File, v4.2.1". 5 March 2000. Retrieved 23 June 2015.

^ Raymond, Eric S. (1996). The New Hacker's Dictionary. Cambridge, MA: MIT Press. p. 368. ISBN 0-262-18178-9.







