What happens when you refit the 486dx2/66 cpu?

is your board set to 5v or 3.3V? because the dx2 66 come in 5v and 3.3V so not sure which one you running, 586 is 3.3V only hope your not trying to run them at 5v?

also duke nukem 3d in svga mode runs just ok on 133 if you click it to 160mhz it is quiet playable

Caluser2000 wrote:

What happens when you refit the 486dx2/66 cpu?

When I configure it for a 486/66 runs great but that is because I'm using the real 486/66

treeman wrote:

is your board set to 5v or 3.3V? because the dx2 66 come in 5v and 3.3V so not sure which one you running, 586 is 3.3V only hope your not trying to run them at 5v?

also duke nukem 3d in svga mode runs just ok on 133 if you click it to 160mhz it is quiet playable

For the 486/66 is set to 5v and with the AMD which does not start is set to 3.3 and the jumper configuration is different from the one in the 486

And talking of DN3D yes with 133 works great but with the 486/66 it becomes choppy

Thats pretty normal for a DX66 to be choppy in DN3D at 640 x 480. It just doesn't have the pixel pushing power needed for that mode.

At 320 x 200, a 486 DX2/66 runs duke3d pretty ok ... not amazing, but certainly playable.

I prefer a fast Pentium/Pentium II for duke3d ... can really crank it up high and run silky smooth.

I know, I do run Duke3D on a P233 and works great :3

if the 5x86 is cold its not a good sign, do you have a motherboard to confirm 5x86 working? also try setting fsb to 25mhz for 5x86

is it Intel dx2 66 or amd? you might have to set jumpers for a amd CPU also if you have them set for a Intel

Actually, some AMD CPUs at that time period, the DX5-133 or Am5x86-P75, was only 3.45V, so in order to use it on a 5V line, the one way to use the CPU is a 3.45V to 5V voltage regulator that fits into the socket. Another option is to buy an Evergreen 586 that has 5V and it'll work without issues.

Yeah Evergeen, Hypertech or Kingston x586 upgrades have a voltage reg on the interposer. My Hypertech Hyperace 586 comes with a fan. Useful page for those interested in this type of upgrade http://www.cpushack.com/UpgradeProcessors.html

so in theory under clocking it at 25fsb might help wake it up if it really needs 3.45V however I got. about 6 586 chips and none of them ever complained about running at 3.3V and most of them clocked at 160mhz

Looks more like he put a 3.45v cpu in a 5v system. Hence no video and fans just running.

Nope, I just setted up the board to run at 3.3v via the jumper settings and both AMD's I have do work in an other board that I have iirc, maybe the power is not sufficient for the CPU to warm up I guess

And tomorrow or the Wednesday I'll try the 25 megs setting to see what happens

another thing that comes to mind could be a faulty voltage regulator, not sending power on 3.3v need to measure with a multimeter to confirm you are getting power into socket when jumpered at 3.3v also would be good to try other slower cpu at 3.3V like dx4 100 or dx2 66 3.3v version but not everybody has alot of parts I understand that

Probably the board came in two configurations, one with voltage regulator and one without. The board still has all the jumper settings but they do nothing, because the regulator isn't there to produce the lower voltage

Happened with me on a DataExpert board

lets hope not for the sake of those 5x86 chips, he should of seen some smoke if they did burn up at 5v.
anyway this is a quick way to test if your jumpers are sending the right voltage

treeman wrote:

lets hope not for the sake of those 5x86 chips, he should of seen some smoke if they did burn up at 5v. anyway this is a quick […]
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lets hope not for the sake of those 5x86 chips, he should of seen some smoke if they did burn up at 5v.
anyway this is a quick way to test if your jumpers are sending the right voltage

😳 that board... sitting on fabric... 😳

I tried at 25 MHz... nothing, I'll share a pic of the board's processor area

looks like something missing from factory on u11 need somebody with same board that has confirmed 3.3v capability for comparison