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View Full Version : Turbo button issue on a 486 machine.



barney
October 15th, 2011, 01:56 PM
I have a 486 computer with a DX266 cpu. When I run it full speed, everything is fine. When I press the turbo button to slow it down, it definitely slows waaaaay down. I always figured pressing the turbo button cut the speed in half but on my this machine, it slows it down to the equivalency of a 286 16MHz cpu.
Does this sound normal or is that a little slower that it should be?

Robin4
October 15th, 2011, 02:13 PM
I think it is normal. Because the turbo button was mentioned to use software that was designed for slower systems.. And that what the turbo button do if you put it out.

DOS lives on!!
October 15th, 2011, 02:50 PM
That's what turbo buttons are for. On some desktops, the turbo button was next to a MHz display. When the turbo button is pressed, the number on the display changes. That number corresponds with how fast the computer speed is.

You can also get the MHz display to display anything you want. On the back of it, there's a bunch of jumpers that you can change to get it to display certain letters or numbers. They're pretty fun to play with. :D

Ole Juul
October 15th, 2011, 03:11 PM
I think you guys missed what barney said:

I always figured pressing the turbo button cut the speed in half but on my this machine, it slows it down to the equivalency of a 286 16MHz cpu.
So, he is aware that it slows it down. The question is "how much". I thought it was supposed to be down to 4.77MHz, but I'm not sure either.

krebizfan
October 15th, 2011, 06:31 PM
My 486 computers with turbo buttons have different effects. The Gateway system drops the bus speed to 8 MHz. The unlabeled system with a Blue Lightning installed drops the CPU multiplier changing the clock speed from 75 MHz down to an anemic 25 MHz. I think most of the early (1990 or earlier) 386 and 486 along with some fast 286 systems all switched to a bus speed of 8 (maybe 6) MHz because that provided the best stability with expansion cards.

NeXT
October 15th, 2011, 06:36 PM
I have seen some turbo buttons do the most common thing which was switch off the cache.

barney
October 16th, 2011, 03:35 AM
I was doing system speed test on Norton Utilities and in normal 66mhz mode, my system gets a speed result of 128. When I press the turbo button, I get a speed score of 8.8 (which is equivalent to my 286 16mHZ).

It's no big deal, I just wish the slowdown speed was equivalent to a 486 25mhz, or maybe a fast 386 33MhZ.