Did you try a real intel dx2?

I'm not an expert but both CPUs can be 3.3v or 5v. Are you sure the Intel CPU isn't 5v and the AMD 3.3v? That would explain the excessive heat.

Am486DX2-66 - AMD"RDF feed
base frequency 66 MHz (0.066 GHz, 66,000 kHz) +
bus rate 33 MT/s (0.033 GT/s, 33,000 kT/s) +
bus speed 33 MHz (0.033 GHz, 33,000 kHz) +
bus type FSB +
clock multiplier 2 +
core count 1 +
core name 486DX2 +
core voltage 5 V (50 dV, 500 cV, 5,000 mV) +
designer AMD +
family Am486 +

the motherboard had a dx2 33mhz intel same thing but showing the correct speed for that cpu 33/44mhz
i dont see any jumpers to change for the cpu ?
maybe the motherboard only shows the speed etc when i install a os /hdd etc etc
cant find any info on the mobo
motherboard gives me no beeps so thats a good thing i think

i also have a cyrix cx486 dx2v80 but thats a 3.4v cpu ,i think the speed wil ony show if i install a os wich i cant now
wil order a gotek and test some more

Can you please make a photo with the entire motherboard in the frame and without anything going in front of it (especially IDE cables) so we can add it to UH19 (see my signature) ?
A BIOS dump would also be appreciated 😀

We might even be able to identify your board if we have it in our database which would give you access to eventual jumper settings.

Also the reason why the DX2-66 is hot to touch is because it was one of the first CPU where it was recommended to have some sort of cooling solution. You can run it for a while without one, but it's better to install one.

i wil post a pic
dont know what this means
(see my signature) ? << ??
A BIOS dump would also be appreciate << dont know how ,dont have the tools
the blue stuff with the yellow progress bar is the bios ?
i did my best to take pics

...

its all i have 😀

scroeffie wrote on 2021-04-17, 13:41:

i dont see any jumpers to change for the cpu ?
maybe the motherboard only shows the speed etc when i install a os /hdd etc etc

Motherboard BIOS might be old and not aware of DX2 CPUs, so it will display the base frequency instead. And that's 33MHz. From mobo perspective the DX-33 and DX2-66 are identical, the clock multiplier is in the CPU itself.
In other words, just swapping a DX-33 to DX2-66 should work. Maybe the CPU is defective? Did you check if it has all the pins intact?

Also, DX CPUs already run hot and DX2 need at least some heatsink attached. Preferably with fan as well if you don't want it to run at over 65C - the fan can be slow and quiet, all it has to do is help move some air. You might get a DX2 to work for a while without a heatsink but I don't recommend it, you will kill it eventually. For testing you can try just a fan blowing air on the CPU, that will also cool it down considerably.

The CPU shown in the first image is clearly the 5V version. The AMDs version of the 5V DX2 is known to be a hot bastard, even compared to the intel. That's definitely a CPU you don't want to run without fan/heatsink.

I was a little confused by the original post. I got the impression the system wasn't booting.

i tried to install DOS Benchmark Pack
via gotek but its to big to fit on 1 floppy via gotek

why does it say 77mhz ?

The board has both 66 and 80 MHz oscillators.
Did you jumper everything correctly so your CPU uses the 66 MHz oscillator?
It needs 66 MHz : 2 = 33 MHz = Front Side Bus x 2 (internal multi in DX2 CPUs) => 66 MHz CPU operation.

Maybe it´s the jumper below the oscillators or somewhere nearby.

i dont have a manual so i dont know wich jumper to change etc

this motherboard is very picky ,not shure if even a xide card bios wil work some times the install of ms dos wont even boot with a 128mb compact flash card

https://www.ebay.nl/itm/XT-CF-LITE-4-1-Compac … AoAAOSwPw1gVc-c

It's likely that chkcpu is using a method for detecting the CPU speed which fails to consider the inner workings of your CPU. Speedsys is another example where the speed detection routine sometimes fails. The Cyrix 486DLC-40 is detected as 13MHz by this program.
Maybe your AMD DX2 is not an exact clone of the Intel DX2. At some point AMD lost a lawsuit with intel because they were using their microcode, which prompted them to switch their CPUs over to microcode using an in-house design. I believe am386 and am486 were both affected.

scroeffie wrote on 2021-04-17, 17:23:

i wil post a pic dont know what this means (see my signature) ? << ?? A BIOS dump would also be appreciate << dont know how […]
Show full quote

i wil post a pic
dont know what this means
(see my signature) ? << ??
A BIOS dump would also be appreciate << dont know how ,dont have the tools
the blue stuff with the yellow progress bar is the bios ?
i did my best to take pics

Below my messages, there is this text "Trying to identify old hardware ? Visit Ultimate Hardware 2019 - Project's thread The Ultimate Hardware 2019 (UH19) project- a stason.org/TH99 alternative" which link to UH19 and UH19's project thread (which contains infos about what UH19 is, how it works, etc).

To dump your bios you can use this software : http://cd.textfiles.com/microhaus/mhblackbox3 … MORY/GETROM.ZIP
Just run it on your 486 and it should generate a bin file that you can send here.

Your photos are useful, but unfortunately the photos of the entire motherboards are really blurry. Can you make a clear one ? The last one is almost there 😀

I couldn't find your motherboard in our database, but I'm willing to add it using your photos 😁

i have gained not 1 step with this motherboard
so i bought some real cf cards i know they are real because i contacted sandisk
all of them are 256 mb and they work 100% in my p1 166 machine
the settings are /256mb/cycls978/head16/prcomp/65535/landz977/sector32 normal not lba
when i pop in the cf card n the 486 the post screes says mass storage hdc fail !
all 256mb cards work in my p1 with ms dos etc 0 problems
the 486 motherboard has a ide connector on the mobo itself i cant test that because i dont have a manual !!
so my only option is by a xtide card ? would that by pass the bios ,iam lost
oh and to look up the correct settings for the cf cards i also used the p1 and a program called IDEINFO

when i pop in the cf card n the 486 the post screes says mass storage hdc fail !

So you have already set the hdd parameters in the bios? Also that error message appears to be custom, it's not a standard one from the bios.

For connecting, make sure the red lining on the IDE cable is in the side of pin 1 (one) of the connector.

yes i have set the correct parameters my p1 gave me via auto chek hdd
than i popped in the cf card in my 486 ,cable is correct red line on pin 1
i also changed the ide cable i also tried another cf card to ide same thing ,also via the gotek starting ms dos install takes for ever
on my p1 its fast the red bios screen is my p1
iam out of ideas 🙁
the 486 bios says 244mb / the p1 says 256mb <witch is correct

on the 486 precomm i cant fill in the complete set of number the last number i cant fill in it wont let me