Editing Turbo button (section)

== Switching ==

On most systems, turbo mode was with the button pushed in, but since the button could often be wired either way, on some systems it was the opposite. The turbo button could be linked to a turbo LED or two-digit [[segmented display]] on the system case, although in some cases, the indicated frequency (in MHz) was not a measure of the actual processor clocks, but the two "fast" and "slow" display options set by [[Jumper (computing)|jumpers]] on the [[motherboard]].

Some systems also supported keyboard combinations {{keypress|Ctrl}}-{{keypress|Alt}}-{{keypress|+}} and {{keypress|Ctrl}}-{{keypress|Alt}}-{{keypress|-}} for switching turbo mode on and off, such as the Packard Bell 486ES 3x3 (the 4x4 and MT models had a dedicated Turbo button). With all the 486ES models—those with and without a turbo button—the power light would show green in normal (“Turbo”) mode, and orange in Slow mode.<ref>Packard Bell 486ES Personal Computer User’s Manual, pp. 4-1 to 4-3</ref> ITT Xtra used {{keypress|Ctrl}}-{{keypress|Alt}}-{{keypress|?}} to toggle.{{citation needed|date=November 2014}}

Some keyboards had a turbo button as well, located near right {{key top|Shift}}. Unlike the turbo button that was common on computer cases, the turbo button on the keyboards did not control the [[clock rate]] of the CPU; rather, it controlled the keyboard repeat rate.<ref>{{cite magazine|last=Case|first=Loyd|date=2006-05-09|title=Keyboards For Less|url=https://books.google.com/books?id=WBftkMjnokEC&pg=PA87|magazine=PC Magazine|publisher=Ziff Davis|page=87|access-date=2018-01-07|quote=When you press the Turbo button simultaneously with one of the first seven Function keys, you can increase or decrease the speed of repeated keys.}}</ref>