[IBM] The power switch on a computer, esp. 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." Sources at IBM report that, in tune
with the company's passion for {TLA}s, this is often abbreviated as
BRS (this has also become established on FidoNet and in the PC
{clone} world). 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}; see also {scram
switch}.
[glossary]
[Reference(s) to this entry by made by: {BRS}{molly-guard}{power cycle}{scram switch}]