A lace card (also called a whoopee card, ventilator card, flyswatter card, or IBM doily) is a
punched card
A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widel ...
with all holes punched. 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.
See also
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Black fax
A black fax is a prank fax transmission consisting of one or more pages entirely filled with a uniform black tone. The sender's intention is generally to use up as much of the recipient's fax ink, toner, or thermal paper as possible, thus costi ...
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Christmas tree packet
Christmas is an annual festival commemorating Nativity of Jesus, the birth of Jesus Christ, observed primarily on December 25 as a Religion, religious and Culture, cultural celebration among billions of people Observance of Christmas by coun ...
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Denial of service
In computing, a denial-of-service attack (DoS attack) is a cyberattack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host co ...
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List of practical joke topics
This is a list of practical joke topics (also known as a prank, gag, jape, or shenanigan) which are mischievous tricks or jokes played on someone, typically causing the victim to experience embarrassment, perplexity, confusion, or discomfort.
Pr ...
Notes
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References
Punched card
Practical joke devices
Denial-of-service attacks
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