Big Red Switch from FOLDOC

Big Red Switch

(BRS) IBM jargon for the power switch on a computer, especially the "Emergency Pull" switch on an IBM mainframe or the power switch on an IBM PC where it really is large and red.

"This !@%$% bitty box is hung again; time to hit the Big Red Switch."

It is alleged that the emergency pull switch on an IBM 360/91 actually fired a non-conducting bolt into the main power feed; the BRSes on more recent mainframes physically drop a block into place so that they can't be pushed back in. People get fired for pulling them, especially inappropriately (see also molly-guard).

Compare power cycle, three-finger salute, 120 reset; see also scram switch.

[Jargon File]

Last updated: 2014-08-10

Nearby terms:

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