The informal predecessor to
Ctrl-Alt-Delete. On
Apple II era machines, all the peripherals were in primitive ISA type slots on the main mother board. Due to one reason or another, sometimes the cards in these slots (typically limited to a modem, a
80 column card and possibly a
printer or
super-serial card), would wiggle, causing the machine to hang.
Solution: Pick up the front of the machine about 3 inches, and drop it, hard onto your desk top. voila. cards reseated. Usually also caused a spontaneous reboot as a fringe time-saving bonus.