Rebirth of a Pentium II - P6DKF Retro Build

[Per Hansson]

Re: Rebirth of a Pentium II - P6DKF Retro Build

I quickly dumped the idea of any further CPU hackery with this and went back to the Klamath 300MHz; natively the fastest this board can take. It only supports 2.8v chips....so that rules out Deschutes or Katmai CPU's.....

It should support 400MHz according to the manual:
https://theretroweb.com/motherboards...cro-p6dkf#cpus

[eccerr0r]

Re: Rebirth of a Pentium II - P6DKF Retro Build

I think it was my BX Dual slot-1 board that said my Tualatin 1.2GHz was running an unknown CPU at 44MHz or perhaps something with an improper symbol, alas, it was running a lot faster than 486/50 speeds, actually around full speed. I ignored what BIOS said and relied on how fast it actually ran software.

The socket adapter also dealt with programming the Vcore to a reasonable value as well - it was a Tualatin socket adapter in a slot1 adapter, a stack of crap...

[Topcat]

Re: Rebirth of a Pentium II - P6DKF Retro Build

That board is in such nice condition, would make for a very nice 486 build!
And with a 30 year old still working RTC module, that is just begging to be rebuilt!
Based on the specs it has that must have been really expensive back in the day!

Given the badge on the front bezel, I'd guess it was some kind of controller for medical equipment....so yea, they built the best they could at the time. 16mb RAM and a DX4-100 was a big deal when this was new; didn't come cheap!

I looked on ebay, 486 gear doesn't seem to have held much value....so I wouldn't waste my time making a listing for it....I'll bag it up and shelf it. If I come across a smaller AT case for it, I might do a nice DOS box with it...but no way I was wasting this awesome case for a 486!

Back to this one.... I found its quirk. All 8 SIMM slots filled (1GB total), that's what was causing the slowdown. Not sure why. It was painfully slow!! I wasn't expecting much from this, but it was not performing well at all; certainly nowhere it should be. Moving any data around was agonizing; IDE or SCSI interface. RAM memtested fine....but as the process of elimination, I removed half of the modules and this thing came to life; began performing as it should. Thinking maybe there was a wonky module in the mix, I swapped out the 4 I removed....and the result was the same, performed fine. I installed 2 more to make 768mb, that also performed fine.....but all 8 modules, back to agony. While the FX chipset 'officially' supports 512mb, it was well known to be able to run 1gb....but I guess I just got one that wont.

I did get curious and test this with a pair of Mendocino celerons with slotkets. The slotkets used supported 'dual cpu' for PPGA celerons but did not support coppermines at all.... Anyway, It actually ran them dual. I tested with a pair of 500MHz Celerons....saw both CPU's....but no microcode, they showed up as unknown CPU and the fastest I could get the clock speeds to was 360...no that wasn't a typo....360MHz.... I quickly dumped the idea of any further CPU hackery with this and went back to the Klamath 300MHz; natively the fastest this board can take. It only supports 2.8v chips....so that rules out Deschutes or Katmai CPU's.....

[Per Hansson]

Re: Rebirth of a Pentium II - P6DKF Retro Build

it has a micronics 486 motherboard in it with a dx4-100 cpu.... I was never a 486 enthusiast, i had no intentions of doing a build with it....

That board is in such nice condition, would make for a very nice 486 build!
And with a 30 year old still working RTC module, that is just begging to be rebuilt!
Based on the specs it has that must have been really expensive back in the day!

[eccerr0r]

Re: Rebirth of a Pentium II - P6DKF Retro Build

Looks like a standard "AT" full sized board, but yeah that clearance issue would be a problem. Imagine being able to stick one of those in a IBM 5170 case, now that would be a sleeper...alas the hard drive area would be a serious blockage to have that happen.

I would have thought any S370/S1 board would take Tualatins with adapters/mods, alas, without 100MHz FSB one would lose 33% speed.

I don't think I'll be putting my dual slot 1 board in a case anytime soon. Mainly because my Tyan (Via chipset) slot1/s370 board can take more RAM, 3x512MB x4 SDRAM is already acquired versus $ARM$LEG 4x256MB x8 SDRAM is still 2/3 of the RAM. 3 is a weird number for computers yet it comes up now and again.

(Now why there are so many boards out there with only 3 SDRAM slots, why...)

[Dan81]

Re: Rebirth of a Pentium II - P6DKF Retro Build

I think I have an AT Pentium II mainboard as well... a Zida LX98-AT w/ Klamath 266MHz - 440LX at the size of a compact 486

The only thing that would rival it was surprisingly a PCChips M726MRT w/ Aladdin Pro II and funky Slot1/Skt370 combo - amazingly stable for a PCChips board, shame it was limited to Mendocinos and Coppermines - it would've made for quite a interesting AT powerhouse with the right parts. (shhhh.... we don't mention BX around here )

[Topcat]

Re: Rebirth of a Pentium II - P6DKF Retro Build

I have an LG RAM module. It's a 32MB PC100 module from a Compaq.

That 486 system has 4x 4mb 70NS FPM RAM....yea, anyone remember that?!? ...but a total of 16mb RAM was a big deal back in its day!

That's mine, I got it on Ebay years ago for next to nothing, since apparently anything that doesn't say Tektronix or HP isn't worth much (or at least wasn't when I bought this). Being made in 1997 it is pretty late for an analogue CRT based oscilloscope, from what I've seen it appears most of these were sold to universities (who still wanted analogue scopes to teach the "fundamentals" well after digital had largely taken over in the field).

Some pics of the inside:

https://www.badcaps.net/forum/attach...1&d=1679851232

https://www.badcaps.net/forum/attach...1&d=1679851232

https://www.badcaps.net/forum/attach...1&d=1679851232


And the unit in operation (in this case with a wave form generator):

https://www.badcaps.net/forum/attach...1&d=1679851232

Very nice. I thougth I swam against the stream with my Sencore gear....Goldstar scope has me beat.... While I didn't drink the tektronics koolaid either, they do make good gear.

Back to this build....I didn't accomplish a lot even though I spent the bulk of the day on it....the beauty of old hardware, things can be temperamental...but first things first.

Since I am not sure what OS I'll be running on this, I wanted to get the PS2 mouse working. The motherboard has a header for it, but I did not get the dongle for it with the board....and of course the pinout for the motherboard header is nowhere to be found.....and searching, it seems they're all different......so I'll have to make one...

Some PS2 header that had no plug and a USB connector out of a junk case. The internal connector for the PS2 port is identical to a USB....



The scrap wires depinned....



The PS2 round end pinned out....that part was easy, they're all the same. I just had to map the colors, it seems this dongle was different with wire colors....no biggie.



As easy as this seemed, it wasn't. The Vcc and the GND were no problem to find, but I had no idea where the CLK and DATA pins were....so it was a bit of 'trial & error' based on other motherboard pinouts I found....yea, I wasted a good 2 hours on this, but I finally got it.



Connected.



Mouse finally seen!!





Now for a little 'off the cuff' mod....I was looking at the big opening where the original HDD cage was, that won't be reused. It would interfere with the CPU's. This cage opening is right behind the vented front fascia; plenty of air could be drawn in through this....lets see what kind of fan I can install here....and I found one!!

I have a bunch of 140MM Phantek case fans, and as if by some miracle it is an absolute perfect fit over this opening without having to modify the case at all!!

The fan:




All I had to do was slip a washer over the head of the fan screws, like so:



Looks like it was born there!!





Now for something old, worthless, cool, and new!! A Matrox G200 G4 quad display GPU. I got it for peanuts on fleabay, new old stock. These were fabulous 2D cards back in the era of this motherboard.



Shiny & new.....even if it is ~25yrs old!



Putting things together in test form....I want to see what works well with what....





Original front fan had to be replaced, it was frozen up and I couldn't get it to work right again....so I just trashed it and put another one in. Just a common 90mm.



...and that was about all...

Been OS experimenting.... NT4 runs nice on this, as expected.....but win2k is a bit painful.....not that I expected miracles, but it seems a bit slower than it should be.....but I have to remind myself, it's EDO RAM, 66MHz FSB, FX chipset, and a Klamath Pentium2!! Odds are it'll be a NT system in the end, but I want to tinker with Win2k some more....but to give you an idea, the install took ~2hrs for it to do its full song & dance! I know this thing is slow....but it shouldn't have taken this long....something is up.

[dmill89]

Re: Rebirth of a Pentium II - P6DKF Retro Build

I like the Goldstar scope....is that yours or just some random image you found on the interwebs? If yours, neat piece of tech history. I always thought 'LG' stood for 'Lifes Good'.....

That's mine, I got it on Ebay years ago for next to nothing, since apparently anything that doesn't say Tektronix or HP isn't worth much (or at least wasn't when I bought this). Being made in 1997 it is pretty late for an analogue CRT based oscilloscope, from what I've seen it appears most of these were sold to universities (who still wanted analogue scopes to teach the "fundamentals" well after digital had largely taken over in the field).

Some pics of the inside:








And the unit in operation (in this case with a wave form generator):

[lti]

Re: Rebirth of a Pentium II - P6DKF Retro Build

I have an LG RAM module. It's a 32MB PC100 module from a Compaq.

I didn't know Fuhjyyu had been around that long, and it's surprising to see a 300W power supply that's that old.

[Topcat]

Re: Rebirth of a Pentium II - P6DKF Retro Build

They were one of the two companies that merged to form LG (which stands for Lucky-Goldstar), though I haven't really seen LG branded ram either. They also made test equipment such as this oscilloscope (which was made just after the merger/re-name to LG so the label on the back says LG precision, while the faceplate still has the old GoldStar name, later production of these had LG faceplates).

https://www.badcaps.net/forum/attach...1&d=1679805653

https://www.badcaps.net/forum/attach...1&d=1679805653

https://www.badcaps.net/forum/attach...1&d=1679805653

I like the Goldstar scope....is that yours or just some random image you found on the interwebs? If yours, neat piece of tech history. I always thought 'LG' stood for 'Lifes Good'.....

Definitely looks like an interesting build. I don't think I've ever seen an AT Pentium II board before.

...and a dual CPU one at that....an old specialty of mine! The only other AT slot-1 I ever encountered was back when the BX chipset came out, had a client that wanted to reuse his nice AT case but upgrade to a P2 450 from a P-133. I scoured and found a Soyo BX AT board to make this happen....it was the only one I could find. I don't remember the model.

That should be old enough to pre-date water-based electrolytes so that may explain why they held up so well, definitely still a good idea to replace any 37-year-old caps in an SMPS, especially a known suspect brand.

Exactly, I wasn't that trusting of them either. They're in the trash. THe only ones I didn't change were the big main filters, as I didn't have replacements of the correct value on-hand. I did check them though.

[dmill89]

Re: Rebirth of a Pentium II - P6DKF Retro Build

I never knew that 'GoldStar' made computer memory. I remember Goldstar consumer electronics as a kid (TV's, radios, tape players, etc), but never knew they made computer gear. Interesting.

They were one of the two companies that merged to form LG (which stands for Lucky-Goldstar), though I haven't really seen LG branded ram either. They also made test equipment such as this oscilloscope (which was made just after the merger/re-name to LG so the label on the back says LG precision, while the faceplate still has the old GoldStar name, later production of these had LG faceplates).











Definitely looks like an interesting build. I don't think I've ever seen an AT Pentium II board before.

QC sticker says it was manufactured in September of 1986!
....
I recapped it anyway.....but I really have to wonder if Fuhjyuu used to make a quality cap back in the day.

That should be old enough to pre-date water-based electrolytes so that may explain why they held up so well, definitely still a good idea to replace any 37-year-old caps in an SMPS, especially a known suspect brand.

[Topcat]

It's been a LOOOONG time since I've done one of these.... I've had the case for years, its just been sitting in my office with crap stacked on top of it. It has a Micronics 486 motherboard in it with a DX4-100 CPU.... I was never a 486 enthusiast, I had no intentions of doing a build with it....I only kept it for the case....which someone dropped off for recycling years ago.

Anyway, I recently stumbled upon a Supermicro P6DKF AT motherboard and tested it in 'the oven'. I remember seeing one (or one similar) back in the 90's before eATX was a twinkle in anyone's eyes and wondering what case it would take to house this....well here we are!! This is a rather unusual board, ran across it on ebay inadvertently...and it was definitely cheap enough and I know I'd likely never see another one, so I grabbed it....and here we go!!

Not sure who makes this, but given the stupid drive rails it screams out Enlight....but I'll get back to that debacle later....

Nice big beige full tower; AT form factor.





The 486 innards....



Time to disassemble this. The lower cage removed, I'm guessing this held the HDD's, although it still used those dumb drive rails, but has no access from the front panel. This won't be reused, it'll interfere with the AT (aka full AT) motherboard.



Board out.



I never knew that 'GoldStar' made computer memory. I remember Goldstar consumer electronics as a kid (TV's, radios, tape players, etc), but never knew they made computer gear. Interesting.



Ok, little tangent....I'll atleast see if this works.....in the oven...



It POST's and in the BIOS. No, I did not set the date/time!! It was only off by a few hours....the RTC chip/battery is still good!



It's only drawing from the +5V rail. Idled around ~3A. Loaded 'troubleshooter', and under testing never went above 6A. Apparently these aren't power hogs.



Holy Slow, Batman!!! ...but it did run!!



Back to the task at hand....and the drive rails mess. These are the rails that are needed....and I have enough for 2 5.25" drives, which won't be the ones shown with the case. I have a nice matched set of Plextor opticals that will go in this....which still leaves me needing atleast one more pair to hold the HDD...



These were the closest thing I had on-hand, and of course they aren't the same....so some fabrication will have to be done....but I'll figure that out during the reassembly phase.



Size difference in the boards. The 486 is a baby AT; as are all AT's without the mass above the keyboard port, even if longer, they're still considered 'baby AT'.



Back to dismantling the case in prep for cleaning. The case was filthy inside.



I don't remove the case badges anymore like I used to....they add a charm & elegance that's long gone these days.



Yea...filthy! Front filter.



I took it outside and cleaned it with the hose & simple green. Dried with the air compressor & microfiber cloth.



It cleaned up well. I couldnt believe that filter cleaned up and not just disintegrate in my hands as I cleaned it in hot water with simple green. The water looked like chocolate milk!!



Now for the power supply. It's a 'topower' rated at 300W...



QC sticker says it was manufactured in September of 1986! Wowza! Makes me wonder if this 486 wasn't the first system in this case; as that is dated ~1992 according to the BIOS and other data suggests 1993 as well.... A mystery that will never be solved perhaps....



PSU inside.... The way this is laid out, any normal AT or even ATX PCB could be mounted in here....good to know if the PSU ever dies and I can't fix it.... It is loaded with 'Fuhjyyu' caps, which of course is a big red flag!!



I scoped the unit with no load on it.....All 3 rails aere quiet as can be! I was shocked (no pun intended)!



Inside of the housing....



I recapped it anyway.....but I really have to wonder if Fuhjyuu used to make a quality cap back in the day. I checked the old ones with my Sencore LCR as I pulled them, they were all perfectly in spec with value, no leakage (electrolyte or current), and quality bungs... I was half temped to just put them back in the PSU...but just couldn't bring myself to....

Recapped...



Cleaned up and back together.



I knew there was a reason I didn't miss dealing with AT cases....those silly plastic standoffs they all used!!



I do have a nice stash of them though...



The case had 3 screw-down mount points and the rest are all the plastic pegs....but what a nice snug fit!





This is where I knocked off for the day.......