VOGONS


Meh K6-2 machine

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First post, by andrea

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Hello to all 😀 , after lurking this site for a long time I've finally decided to register and post about my K6 computer.
I call it a "meh" computer because its parts were chosen mainly on a "what can I get for free and/or €verylittle", rather than going for the best. Still, all things considered, I feel like it's a nice honest machine, and it could be a lot worse (i.e. it's not a PC-chips with a chipset of dubious provenance, and its cache seems to be real).

Spec-wise its parts are:

  • A DFI P5BTX/L Rev B+ (i430TX)
  • AMD K6-2 (CXT) 333/AFR-66 (Running at 83*4,5 and 2,6V for 375 MHz)
  • 96 MB of random RAM (64 MB PC133 and 32 MB of PC66)
  • Diamond Monster 3D Voodoo 1 4 MB
  • ATI Rage XL 8 MB (one of those cheap ebay ones)
  • 3com 3C905B-TX NIC
  • Generic Yamaha YMF-718 Soundcard
  • LG 52x CD-ROM, one of those that used to be everywhere
  • 40 GB Maxtor Fireball 3 Slim HDD (only disk I had that didn't complain of a 41+ MHz PCI Bus)
  • 3,5" floppy (i think it's either Alps or Mitsumi, can't remember)
  • Average AT minitower chassis
  • All running First Edition Windows 98

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Side view, if you look closely you can also see a very high tech CPU fan speed controller.

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Rear View

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Incredibly noisy completed picture

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System properties

After building this computer I would like to add a few things:
The Rage XL isn't half as bad as I would have expected it to be, but if you buy an ebay special be aware that they (or at least mine, but I think they're all made by the same people using salvaged chips and the cheapest pcb they can get away with. It's not like there's a massive market for them) need a PCI slot that provides 3,3 V. This mainboard did not. A first test involved a china-special DC-DC converter and a wire soldered to the Rage's voltage regulator. This worked but the picture was quite shaky, probably due to inadequate filtering. After replacing the main filter cap (100 μF 6,3 V IIRC) with a bigger one (1000 μF 6,3 V, probably too much but what I had on hand) the noise went away.
After measuring the current draw on the 3,3V converter and finding out it was very low, I realised that there must be a 3,3 V regulator already on the motherboard for the CPU I/O, SDRAM and the like. Once i found it, I soldered a couple wires going from it to the pins that are supposed to provide 3,3 V on the PCI slot the card's in (they were otherwise NC) so now the whole thing works just like a bought one.
Also they seem to work only with later driver revisions, at least in this configuration. If you want one to play with ATI3DCIF stuff maybe these aren't for you.

The motherboard: when I first got it gave me the same feeling I had with another old (old as in before the UV-everything LanParties) DFI board. I can't really explain it, but it was something like "I guess it works but it doesn't look all that trustworthy". On a whim I decided to replace all the no-name capacitors around the CPU with ones salvaged from a dead ASUS A7S-VM. On paper this seemed like a good idea: They're only 17 years old, rather than 21, they're from a good brand (a mixture of Rubycon and NCC, with a couple of Panasonics thrown in just because), they didn't live all their life touching the heatsink of a linear voltage regulator and/or CPU, and they're 1500 rather than "1000" μF. Well, after doing this mod the motherboard works like new if not better! Before it would crash if you just looked at it funny (and didn't even think about POSTing at 83 Mhz FSB no matter what was the Vcore), whereas now it runs rock solid at those very same 83 MHz.

The chassis: I don't know if the designers were sadists or if the metal was stamped by Gillette, but it enjoys slicing fingers. A lot. So if you have one, be careful.
I also removed the full-lenght card holder that clipped on the front metal and drilled a 76mm hole for a 80 mm fan.

Thank you all for reading and sorry if there are any mistakes, as English is not my native language. 😀

Reply 1 of 10, by Munx

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The under-powered "meh" builds are the ones that are the most fun!

This looks like a machine on which you'd be playing Quake 2 online after the sun has set and your homework was still not done 🤣

My builds!
The FireStarter 2.0 - The wooden K5
The Underdog - The budget K6
The Voodoo powerhouse - The power-hungry K7
The troll PC - The Socket 423 Pentium 4

Reply 2 of 10, by D3FEKT

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I love underwhelming machines as much as overpowered ones, to me it's got more nostalgic feel as I was poor when I first got into computers, was still using a K6 350mhz system in 2004
Not much has changed, still poor but computers are alot cheaper now 🤣

Reply 3 of 10, by PcBytes

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Those 2 USB ports ghetto mounted in the back... 🤣

"Enter at your own peril, past the bolted door..."
Main PC: i5 3470, GB B75M-D3H, 16GB RAM, 2x1TB
98SE : P3 650, Soyo SY-6BA+IV, 384MB RAM, 80GB

Reply 4 of 10, by andrea

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PcBytes wrote:

Those 2 USB ports ghetto mounted in the back... 🤣

🤣 I even took a little time to file the edges of the bracket... cut with tin snips.

D3FEKT wrote:

I love underwhelming machines as much as overpowered ones, to me it's got more nostalgic feel as I was poor when I first got into computers, was still using a K6 350mhz system in 2004
Not much has changed, still poor but computers are alot cheaper now 🤣

Not only they're cheaper, but they last a lot longer aswell. I still can't wrap my head around the fact that Core 2s came out 12 years ago and yet they're still good for day-to-day usage.

Munx wrote:

The under-powered "meh" builds are the ones that are the most fun!

I think in general making low-endish stuff do things it was never designed to do (for example overclocking OEM boards by messing around with BSEL pins, or voltage adjustment by soldering resistors between Vsense and ground) can be more fun than going plug-and-play with top of the line everything. Or maybe I'm just cheap. Probably the latter.

I'm glad that people enjoyed this. 😊

Andrea

Reply 5 of 10, by leileilol

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The case is certainly on point at least. I've seen a few K6-2 rigs in the day with that design. You just need a Viewsonic CRT ~17" and a Microsoft Internet keyboard now. 😀

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FUCK "AI". It is a tool of fascism. We do not need it. We do not use it.

Reply 6 of 10, by dr_st

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My K6-2 case is amazingly similar, except it is the mid-tower version with an extra bay (unused) and some extra width. It also has extra perforation on the side panel for ventilation (or, mostly, dust collecting).

Two thumbs up for generic beige cases! 🤣

https://cloakedthargoid.wordpress.com/ - Random content on hardware, software, games and toys

Reply 7 of 10, by kolmio

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Thank you for sharing this!

andrea wrote on 2018-06-09, 18:10:
PcBytes wrote:

Those 2 USB ports ghetto mounted in the back... 🤣

🤣 I even took a little time to file the edges of the bracket... cut with tin snips.

How did you mount the bracket in place?
Did you drill holes in it and then used nuts or some other way?

Windows 95 | Chaintech 486SPM M102.A | AMD-X5-133ADW or Am486DX4-100 | 48MB SIMM FPM | ATI Rage 3D II+DVD | CT4100 | 8GB CF

Windows 98 | Acorp 6BX86 | Pentium III 900, slotket | 512MB PC100 | Radeon 9250 | SoundForte SF16-FMI-03 | 64GB MicroSD

Reply 8 of 10, by andrea

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kolmio wrote on Yesterday, 08:36:

How did you mount the bracket in place?
Did you drill holes in it and then used nuts or some other way?

The bracket used to be one of those that goes in a PCI slot opening, before I cut it down.
By pure chance the hole spacing matches with the one for a DB25 port.
Originally the bracked had 2 captive nuts inside the beige rubber moulding, but as I had a screw missing and the threads weren't metric I removed these nuts and put a regular M3 screw with a nut and a washer on the rubber side.

Reply 9 of 10, by Disruptor

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andrea wrote on 2018-06-08, 15:17:

Hello to all 😀 , after lurking this site for a long time I've finally decided to register and post about my K6 computer.
I call it a "meh" computer because its parts were chosen mainly on a "what can I get for free and/or €verylittle", rather than going for the best.

I know it was a nekro post but have you checked whether all of your DRAM is cacheable?
It may be that only 64 MB of RAM can be cached on that machines. That means that every application that is placed above cacheable area of memory will run slower. And on K6/K6-2 that is significant.
You may verify that with a tool like heise's ctcm:
https://ftp.heise.de/ct/ctsi/ctcm17a.zip

Reply 10 of 10, by andrea

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Disruptor wrote on Yesterday, 20:00:
I know it was a nekro post but have you checked whether all of your DRAM is cacheable? It may be that only 64 MB of RAM can be c […]
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I know it was a nekro post but have you checked whether all of your DRAM is cacheable?
It may be that only 64 MB of RAM can be cached on that machines. That means that every application that is placed above cacheable area of memory will run slower. And on K6/K6-2 that is significant.
You may verify that with a tool like heise's ctcm:
https://ftp.heise.de/ct/ctsi/ctcm17a.zip

Thank you.
Yes I know Intel kneecapped the TX so that it can cache only 64MB, but i remember doing some tests (the machine is currently half disassembled) and 96MB was a good compromise between capacity and performance. 128+ is when it starts falling down on its face.
I'd imagine (may be nonsense) that yes, Windows sits in the uncached area, but then applications running are mostly cached.

I don't have raw numbers to quote but this was the overall idea.