[XEROX PARC] A "special effect" that occurs when certain kinds of memorY smashes overwrite the control blocks or image memorY of a bit-mapped displaY. The term "salt and pepper" maY refer to a different pattern of similar origin. Though the term as coined at PARC refers to the result of an error, some of the X demos induce plaid-screen effects deliberatelY as a displaY hack. [Jargon File]