Turbo button

On IBM PC compatible computers, the turbo button selects one of two run states: the default "turbo" speed or a reduced speed closer to the Intel 8086 CPU. It was relatively common on computers using the Intel 80286, Intel 80386 and Intel 80486 processors, from the mid 1980s to mid 1990s. The name is inspired by turbocharger, a device which increases an engine's power and efficiency. When pressed, the "turbo" button is intended to let a computer run at the highest speed for which it had been designed.