green lightning

n. [IBM] 1. Apparently random flashing streaks on the face of 3278-9
terminals while a new symbol set is being downloaded. This hardware bug was
left deliberately unfixed, as some genius within IBM suggested it would let
the user know that something is happening. That, it certainly does. Later
microprocessor-driven IBM color graphics displays were actually programmed
to produce green lightning! 2. [proposed] Any bug perverted into an alleged
feature by adroit rationalization or marketing. Motorola calls the CISC
cruft in the 88000 architecture compatibility logic , but I call it green
lightning. See also feature (sense 6).

