First post, by fractal5
Hi, I have an old 486 with a DX2 66 MHz CPU. My system has a turbo switch and the case has the old style LED display which displays the frequency depending on the state of the turbo switch.
The previous owner never seems to have taken the time to configure the pins on this turbo LED display. I finally figured out how the myriad of jumpers control the LEDs on the display. However, now I'm confronted with a more simple problem, but one I'm having some surprising difficulty solving.
What frequency does my 486 DX2 66 MHz CPU run at when the turbo switch is NOT enabled?
Is it 33 MHz? 25? 15? What is it? How can I figure this out? I have a copy of the manual for the mainboard, but it doesn't specify.
I've tried to simply power on the system with the turbo switch depressed and released, but it always displays "66 MHz", I'm assuming this is normal behavior.
I've also tried to boot an old floppy with Tom's Linux on it. However it shows 33 bogomips with the turbo switch pressed and released, even when I boot from scratch with the turbo switch off or on all the way until the OS has started. I find this a bit strange as I believe the bogomips calculation routine simply sees how many NOP instructions the system can execute in a second. So if the turbo switch was actually working, I would expect to see a different result here.
Unfortunately I'm also having a hard time installing DOS or any other OS on this system so far, so I don't have any way to just run a game or a program to see if it works. I've tried to boot ultimate boot CD, but the isolinux bootloader fails to load as the system appears to be old to load it.
However I'd just really like to know what the frequency it should run at when the turbo switch is not pressed so I can finish up with this turbo LED display and move on to putting the computer fully back together before I install an OS on it.
