The 486 that [someyob] is restoring had the Turbo button, but sadly there was just a simple LED to show whether or not it was engaged. But there was a window in the front panel where it seemed ...

Some computers even supported keyboard combinations like Ctrl-Alt-Plus and Ctrl-Alt-Minus for switching the turbo mode on and off ... less common in 486 PCs, and almost extinct by the time ...

Back in the 486 days, it was common to see a “Turbo” button on the front panel ... indicate the computer is running in compatibility mode, and when the LED is on, the screen shows the Cyrix ...