PCs in the 80s and 90s often had a “Turbo” button which when pressed would counterintuitively slow down the processor speed to allow compatibility with older games designed for slower processors.

Turbo button

Case buttons including turbo button

The LED display showing the CPU clock frequency, in MHz, of an Intel 80486 based computer. The turbo button is the right small button, whereas the left small button is the reset button which still exists in computers as of 2017; the triangular button is the power button.

On personal computers, the turbo button is a button which provides two run states for the computer: normal speed or a “turbo” speed. It was relatively common on personal 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 turbine-driven forced induction device that increases an engine’s power and efficiency.


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12 thoughts on “PCs in the 80s and 90s often had a “Turbo” button which when pressed would counterintuitively slow down the processor speed to allow compatibility with older games designed for slower processors.”

  1. MarvinLazer

    When I was in my early teens, I was one of the top-ranked Mechwarrior 2: Mercenaries players in the world in a league called MAUL, shortly before it shut down. I remember the jump-jets (mandatory for competitive play) had a charge bar that was depleted at a certain rate, and it would fill back up gradually when the jump button wasn’t being pressed.

    I upgraded my computer to something much more modern and powerful shortly after I quit playing competitively, and was surprised that my jump-jets suddenly depleted a *lot* faster. I have a theory that my high performance before then had something to do with running a machine that had a much crappier processor. The processor speed was probably linked to the jump jet depletion rate, and running my bare-bones, minimum system requirement machine gave me an unfair advantage in the form of far more plentiful jump-jet fuel. I’ve often wondered if I would’ve struggled much harder to be successful in competitive play at that game had I upgraded my computer sooner.

  2. rayn13

    I lived through this, and had the button on all the time, wondering why they needed such a button.

  3. TheyAreNotMyMonkeys

    Conveniently next to the “reset button of destruction”….

  4. Saiboogu

    It’s only counterintuitive if you never saw one, or read a poor description — The Turbo button was a toggle button (click to engage, click to disengage) and the default state was “On.”

    So new PCs in that era would ship with a new “Turbo” mode enabled by default, that you could disable if your older program didn’t work right.

  5. Greasemonkey_Chris

    Had a 486dx2 which ran at 100mhz. Always had to press the turbo button and down clock it to 66mhz to play fifa 95

  6. peatthebeat

    Wow I feel old…

    We would use it for Stunts, as the whole 33 Mhz was too quick for the game.

  7. LittleFart

    On some motherboards, the turbo button simply turned off the memory cache rather than actually changing the clock frequency.

  8. i8myface

    I also remember having to edit config.sys for the REM expanded memory for some games that wouldn’t run. Hahha the effort you had to go to get something to work back then, using a dos book, or asking friends haha.

  9. thesupplyguy1

    I remember having a 386 SX 25 and wanting really bad to get the “math co-processor” to make it a “DX”.

  10. drygnfyre

    Pretty much every PC from 1984-94 had a turbo button and a key lock. And was surely a beige box. I think my family’s first PC was a Packard Bell circa 1995-96, so it was a beige box but lacked the turbo button and key lock. (Though it did have the then-new Win95).

  11. 51Cards

    That’s somewhat backwards. The turbo button would set the processor to its higher clock speed so you would leave it on all the time, unless you needed to slow the machine down then you would take it out of Turbo mode.

    Source: I spent my teen years in a computer store building, selling and repairing said machines.

  12. drlongtrl

    When they phased out these hardware button type brake pedals, I remember my go to German pc gaming magazine actually putting a small tool on their cd that came with the mag called “software brake” or some such. And what it did was, it actually used some adjustable percentage of the CPU power, so that with only so much power left, you could actually play older games that relied on processing cycles for their in game timing.

    Oh man, now I’m thinking about how exciting it was back then to go to the store once a month to get the newest issue of that magazine, complete with a cd with demo versions of games on it, sometimes even a full game for free. Those were the days.

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