• Regrettable_incident@lemmy.world
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          4 months ago

          I could be misremembering but I seem to recall the digits on the front of my 486 case changing from 25 to 33 when I pressed the button. That was the only difference I noticed though. Was the beige bastard lying to me?

          • frezik@midwest.social
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            4 months ago

            Lying through its teeth.

            There was a bunch of DOS software that runs too fast to be usable on later processors. Like a Rouge-like game where you fly across the map too fast to control. The Turbo button would bring it down to 8086 speeds so that stuff is usable.

            • Regrettable_incident@lemmy.world
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              4 months ago

              Damn. Lol I kept that turbo button down all the time, thinking turbo = faster. TBF to myself it’s a reasonable mistake! Mind you, I think a lot of what slowed that machine was the hard drive. Faster than loading stuff from a cassette tape but only barely. You could switch the computer on and go make a sandwich while windows 3.1 loads.

              • takeda@lemmy.world
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                4 months ago

                Actually you used it correctly. The slowdown to 8086 speeds was applied when the button was unpressed.

                When the button was pressed the CPU operated at its normal speed.

                On some computers it was possible to wire the button to act in reverse (many people did not like having the button be “on” all the time, as they did not use any 8086 apps), but that was unusual. I believe that’s was the case with OPs computer.

                https://en.wikipedia.org/wiki/Turbo_button

          • macrocephalic@lemmy.world
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            4 months ago

            Back in those early days many applications didn’t have proper timing, they basically just ran as fast as they could. That was fine on an 8mhz cpu as you probably just wanted stuff to run as fast as I could (we weren’t listening to music or watching videos back then). When CPUs got faster (or it could be that it started running at a multiple of the base clock speed) then stuff was suddenly happening TOO fast. The turbo button was a way to slow down the clock speed by some amount to make legacy applications run how it was supposed to run.

            • barsoap@lemm.ee
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              4 months ago

              Most turbo buttons never worked for that purpose, though, they were still way too fast Like, even ignoring other advances such as better IPC (or rather CPI back in those days) you don’t get to an 8MHz 8086 by halving the clock speed of a 50MHz 486. You get to 25MHz. And practically all games past that 8086 stuff was written with proper timing code because devs knew perfectly well that they’re writing for more than one CPU. Also there’s software to do the same job but more precisely and flexibly.

              It probably worked fine for the original PC-AT or something when running PC-XT programs (how would I know our first family box was a 386) but after that it was pointless. Then it hung on for years, then it vanished.