SL prefix or suffix is probably denoting basic power management support, which I believe most DX4 have apart from some early intel ones. So probably that's the setting to go for. As long as you've got a regulator fitted at the bottom corner near the CPU so 3.3V will work.

Use the settings for "AMD Enhance 486 DX" on page 2-17 of the manual (it's on TRW).
Set the voltage to 3.45 V according to page 2-20.
That should be pretty much it.

BitWrangler wrote on 2024-12-03, 20:33:

SL prefix or suffix is probably denoting basic power management support, which I believe most DX4 have apart from some early intel ones. So probably that's the setting to go for. As long as you've got a regulator fitted at the bottom corner near the CPU so 3.3V will work.

Great, thanks! As for the regulator you mentioned, I can see a regulator there, but there also appears to be a blank spot for another one. Is the existing one a 5V regulator and the empty spot is for a 3.3V one?

watson wrote on 2024-12-03, 20:39:

Use the settings for "AMD Enhance 486 DX" on page 2-17 of the manual (it's on TRW).
Set the voltage to 3.45 V according to page 2-20.
That should be pretty much it.

Excellent, thank you!

alfiehicks wrote on 2024-12-04, 10:41:

BitWrangler wrote on 2024-12-03, 20:33:

SL prefix or suffix is probably denoting basic power management support, which I believe most DX4 have apart from some early intel ones. So probably that's the setting to go for. As long as you've got a regulator fitted at the bottom corner near the CPU so 3.3V will work.

Great, thanks! As for the regulator you mentioned, I can see a regulator there, but there also appears to be a blank spot for another one. Is the existing one a 5V regulator and the empty spot is for a 3.3V one?

It's going to be lower than 5V, it looks like that might be a settable one in the 3-4V range. The empty spot might be for a fixed point one for a cheaper version of the board, or might be for an alternate part in case they couldn't get the preferred one.

BitWrangler wrote on 2024-12-04, 13:48:

alfiehicks wrote on 2024-12-04, 10:41:

BitWrangler wrote on 2024-12-03, 20:33:

SL prefix or suffix is probably denoting basic power management support, which I believe most DX4 have apart from some early intel ones. So probably that's the setting to go for. As long as you've got a regulator fitted at the bottom corner near the CPU so 3.3V will work.

Great, thanks! As for the regulator you mentioned, I can see a regulator there, but there also appears to be a blank spot for another one. Is the existing one a 5V regulator and the empty spot is for a 3.3V one?

It's going to be lower than 5V, it looks like that might be a settable one in the 3-4V range. The empty spot might be for a fixed point one for a cheaper version of the board, or might be for an alternate part in case they couldn't get the preferred one.

I had noticed that there's actually an array of jumpers right above the regulator, and they're silkscreened "5v" and "3v" - you can see them in my previous image, although partially obscured by my bodgy external battery extension cable. I thought they might be some kind of voltage control, but I assumed it was for switching between two different regulators. All of the jumpers are currently on the "3V" pins, which is a bit strange given the fact that there's a 5V chip in there right now, but I assume it's just inverted logic.

I take it I should be good to go with putting the DX4 in, as long as the jumpers are set right?

Yup.

It's annoying when manuals give you jumpers "by rote" like only a listing per what strange name they're calling a particular CPU, rather than breaking them all out in list of voltage settings, list of clock settings, list of CPU feature settings etc, some do both so you can double check, but when you've got something that's a little different, it's a pain in the butt to have to analyse every CPU jumper list to figure what means what.

the chip that's currently installed is getting 3V, the jumpers are not "inverted"

maxtherabbit wrote on 2024-12-04, 14:27:

the chip that's currently installed is getting 3V, the jumpers are not "inverted"

Yes - as soon as I posted that reply I second-guessed that. The chip in there right now is a 486 DX2-66, and I thought they were all 5v but apparently not. I have no idea what it specifically is because it's got a permanently affixed heatsink and I haven't run any hardware analysis programs or anything.

BitWrangler wrote on 2024-12-04, 14:26:

Yup.

It's annoying when manuals give you jumpers "by rote" like only a listing per what strange name they're calling a particular CPU, rather than breaking them all out in list of voltage settings, list of clock settings, list of CPU feature settings etc, some do both so you can double check, but when you've got something that's a little different, it's a pain in the butt to have to analyse every CPU jumper list to figure what means what.

Indeed. Thanks for all your help, though, I really appreciate it as a first-timer to this sort of thing!

I would check it with CHKCPU, if it's a 16kb cache AMD DX2 it might be a better DX4 than the DX4 you're trying to put in... they downbinned some later cores to fulfill DX2-66 market demand.

BitWrangler wrote on 2024-12-04, 14:39:

I would check it with CHKCPU, if it's a 16kb cache AMD DX2 it might be a better DX4 than the DX4 you're trying to put in... they downbinned some later cores to fulfill DX2-66 market demand.

Oh, interesting. I'm currently waiting on a CF card adaptor to arrive but as soon as it does, I'll check it - the fact that the heatsink is permanently attached on the current one when it isn't on the DX4-100 is quite suspicious. I'd have checked it before, but the CD-ROM in the machine won't read CD-Rs, and the only other free CD drive I've got was constantly erroring out every time I tried to copy anything to the hard drive.

alfiehicks wrote on 2024-12-04, 14:44:

BitWrangler wrote on 2024-12-04, 14:39:

I would check it with CHKCPU, if it's a 16kb cache AMD DX2 it might be a better DX4 than the DX4 you're trying to put in... they downbinned some later cores to fulfill DX2-66 market demand.

Oh, interesting. I'm currently waiting on a CF card adaptor to arrive but as soon as it does, I'll check it - the fact that the heatsink is permanently attached on the current one when it isn't on the DX4-100 is quite suspicious. I'd have checked it before, but the CD-ROM in the machine won't read CD-Rs, and the only other free CD drive I've got was constantly erroring out every time I tried to copy anything to the hard drive.

Well, CHKCPU says it's got no CPUID, so I suppose I didn't get lucky. It bothers me that I'll basically never know the exact manufacturer or specs. I suppose I'll just need to stick a label underneath with the info written on it and hope that they never get separated. Dumb.

DX2 that predates CPUID makes Intel the highest probability.