The Free On-Line Dictionary of Computing has this to say about "chad"
( http://www.foldoc.org ) :

  "Chad - <jargon, printer> /chad/ (Or "selvage" /sel'v*j/
  (sewing and weaving), "perf", "perfory", "snaf").

  1. The perforated edge strips on paper for sprocket feed printers,
  after they have been separated from the printed portion.

  The term perf may also refer to the perforations themselves, rather
  than the chad they produce when torn.

(Why "snaf"?)

  2. (Or "chaff", "computer confetti", "keypunch droppings")  The
  confetti-like bits punched out of punched cards or paper tape which
  collected in the chad box.

One of the Jargon File's correspondents believed that "chad" derived
from the Chadless keypunch:

  Chadless keypunch <hardware>  A card punch which cut little U-shapes
  in punched cards, rather than punching out a circle or rectangle.
  The U's made a hole when folded back.

  Obviously, if the Chadless keypunch didn't make them, then the stuff
  that other keypunches made had to be "chad". The assertion that the
  keypunch was named after its inventor is not supported by any
  record in US or UK patents or surname references.

About the Free On-line Dictionary of Computing:

  "FOLDOC is a searchable dictionary of acronyms, jargon, programming
languages, tools, architecture, operating systems, networking, theory,
conventions, standards, mathematics, telecoms, electronics,
institutions, companies, projects, products, history, in fact anything
to do with computing.

  The dictionary has been growing since 1985 and now contains over
13000 definitions totaling nearly five megabytes of text. Entries are
cross-referenced to each other and to related resources elsewhere on
the net."

  This dictionary is Copyright 1993 by Denis Howe. Individual
definitions from this dictionary may be used without restriction
provided no more than twenty are used in any one work.

This is a terrific site to browse around in and I'm sure the more
computer-oriented members will enjoy it greatly.

Bill (the PinWiz) Kibler