Thinkpads Forum

Tonight was a long, rough night with the 310ED. She came stock with a Pentium 166MMX, and I had a K6-2 500 lying around, so I broke the key pin off of the K6-2 to see what she could do, and sure enough, she boots right up! Of course, I had to wait until the rest of my swag came in the mail before I could do anything with her. Today I received the HDD caddy from Newmode, as well as a hard drive and a couple of sticks of ram from e-bay. My main issue is a lack of a floppy drive. It doesn't come with an integral one, and external ones are rare (and expensive). Luckily, I got a 390E in the mail recently too, with the downside being that it had undisclosed damage to the hinges to the point that the LCD is about to fall off. Other than that (and a dead HDD), it works fine, so I used that to format the hard drive and make it bootable.

Trying to install Windows 98 was an absolute nightmare. It would lock up at totally random times, sometimes while running Scandisk, sometimes while copying files, etc. Absolutely no pattern. And it would do it with both the 166MMX and the K6-2. Finally I got it to boot somewhat stable with the K6-2 and was able to load my rescue CD and run the CPU ID program. It was only reporting it was running at 50mhz bus speed, meaning I was running the Pentium at either 100 or 125 (depending on the multiplier) and the K6-2 at 300mhz (using a 6x multiplier). 2/3 of the time the system wouldn't even post with the Pentium at those speeds.

I guess I was confused both by the amount and orientation of the dip switches. S1 is the voltage dip switch, and is on its own board and labeled. There were two other dip switches right next to the CPU, and I was guessing that the one on top was S3. It turns out I was right about that, but the dip settings listed under the HDD caddy were backwards compared to the switch orientation. Doh!

After setting the dip switch to what I thought was correct, I fired up my rescue CD and ran CPU ID again. Sure enough, I got 66mhz bus speed at 6x, so 400mhz! So, once again, I got the Windows 98 disk running, and I started the install. It finally crashed with 2 minutes left to go with the install, but feeling the laptop, I knew why. She was HOT HOT HOT! Not surprising, seeing as the max load of the Pentium is around 12 watts, and the K6-2 is over 28 watts!!! I have a K6-2+ that should come in the mail tomorrow, and it is a mobile version with a max thermal rating of 18 watts, around 30% more. Hopefully I can help mitigate the heat by taking off the old (and deteriorating) heat pad and just running some of my white Radio Shack heat sink compound.

This has been frustrating at times, but now that I know what I'm doing (I hope), this is becoming fun. This is a VERY worthwhile project for 310ED owners, since a K6-2+ or K6-III should run at least 3x faster than the stock Pentium.

Enough rambling. I'll keep everyone updated once I get the new CPU in and running.

P.S. The 310 series is supposed to run at 19v. I do have the correct voltage power supply on order, and I'm worried that it won't have the current I need for the K6-2+. We'll see. In the mean time, I was using a T41 power supply (16v 72watt) and it seemed to work just fine. The plug seemed looser than it should have been, but again, no known issues power wise using a lower voltage.

The 310ED is really a challenge to play with... because it isn't designed to be easily serviceable, unlike it's 700-series companions. I remember trying to install 98 on mine and just gave up.

I'd appreciate more info on your experiments with this thing, especially with the AMD processors. Getting the K6-2 to work is really a surprise to me, and I'd be interested in seeing just how stable it keeps up with Windows and all the rest.

Interesting that the AMD was consuming all that power, outputting all that heat and running that long before crashing, and no other component in the computer gave out. I'd figure with the 310ED, my lower expectations would be appropriately matched, but I guess not...!

Again, would like to hear more about it. Thanks for sharing.

You're not lying about it not being that easily serviceable. Well, it depends on what is being serviced. I had to change the CMOS battery, and I had to tear the whole thing apart to get at it. I'm just glad I don't have any leftover screws!

As for the K6-2, it's been done before. Several years back, a forum member here, toddyjoe, posted his experiences getting a K6-2 to work.

http://forum.thinkpads.com/viewtopic.ph ... highlight=

There were some Japanese guys as well, and can be found via a Google search.

The trick to getting a K6-2 to work is knowing where the key pin is. The 310ED socket is actually a socket 5, and socket 7 CPUs have an extra pin. It's not electrically connected, and needs to be removed before it'll fit. The main concern is heat and output from the power supply. Also remember that for a K6-2, the 2x multiplier on the motherboard is seen as 6x at the CPU, so 6x times 66mhz bus speed is a maximum of 400mhz, so try to find a CPU already around that speed.

The K6-2+ CPUs seem to run cooler due to a lower voltage. If you want to splurge, you can get an ultra low voltage K6-III+ (1.6v) off of ebay. I just don't know how the 310ED will handle the onboard L2 cache. Something to worry about once I get it running and stable!

Well, fiddlesticks. Now that I got my new CPU in the mail, it doesn't want to post. I did get it to post twice (out of about 25 tries) tonight, doing a round robin between the stock 166MMX, the K6-2, and the K6-2+. I think there is something wrong with the motherboard. After I got it to post with the stock CPU, the only change was I put my HDD, and then it didn't want to post any more. Looks like I'm SOL with this one.

Digitaldrifter

Hmm... well, hopefully the motherboard didn't give out on the abuse from being played with... that's pretty disappointing. Sorry man.

I was aware the 310ED has that socket- I was just not very optimistic other CPUs would work flawlessly. If I was ever going to put in the time to play with the 310ED, I would've bought multiple units, they're very finicky and quite annoying because they can fail without warning if you're not careful... much like A3x, T4x, T61/R61 NVIDIA, my D900T's video cards and most cheap laptops I've come across.

I'm pretty sure you took a lot of precautions... and you shouldn't have to even. I've shorted and really been careless with Thinkpad 760/770, T2x and T30 hardware, even T60s, and all you have to do is unplug it, unplug the CMOS battery, let it sit, and plug everything back in and it starts up fine. Doing that seems to drain any electrical infidelity. You can try that with your 310ED I suppose...

But whether you decide to resume the project or not, hope it goes well. These were some interesting developments.

I declared my 310ED dead after a long bout CPU swapping and trying to get it to post. Forlorn, I scanned E-Bay for other possible candidates. Just my luck, another 310ED (floppy drive included) popped up. I won the auction! The only issue according to the seller was that the HDD was dead.

Sure enough, after turning it on, it has the telltale clicking of a failed hard drive. The only other flaw is that it has a spot with a bunch of dead pixels right where the lid closes over the trackpoint. No biggie, as I kept my old 310ED and can just swap the screen out! The other bad thing; CMOS battery is dead, so now I have to tear down the old one to get it out, then tear down the new one to put it in. Maybe I should just bite the bullet and buy another new one...

More experimenting was warranted. I know the K6-2+ I bought works, as I was able to get it running just fine on my Super 7 machine, however, absolutely no go. What is interesting is with a dead battery and the stock power supply, and with the K6-2+ installed, hitting the power button just caused a brief flash of light. Using the higher rated power supply from my old T41, it was able to juice up enough to keep the lights on, but still no post.

As a backup, I threw in the old K6-2 that gets too hot. Absolutely no issues using the bigger power supply. Well, besides getting too hot, that is. Just tooling around windows it seemed ok, but I tried to install Quake 2 to run a benchmark but got too hot for comfort, so I shut it down.

Now I'm starting to think that the K6-2+ not working on EITHER 310ED isn't a fluke. I don't think it knows what to do with the on-die L2 cache. I know all the rumors from the Japanese sites about getting K6-III's to work, but as I have never heard it confirmed, I am now doubting that it is possible.

Another reason for the impossibility is the voltage situation. The lowest voltage available (without solder mods) is just over 2.1v, way way too high for the low voltage K6-2+ and K6-III+. Unless someone else can chime in about the L2 cache issue, or can show that they or someone else has gotten them to work, it is my opinion that it can't be done, or at least done easily. There may be something in the BIOS that lets you disable the onboard cache, but without the CMOS battery I can't look in the BIOS without it locking up.

Anyways, my next step is to find a mobile version of the K6-2. One I am going to get from E-Bay is the AMD-K6-2/450ADK. It runs at 2.1v and only outputs 16w. Should work very well and not warm up the room as much as my K6-2 AHX (over 28w!!). I'll keep everybody posted.

Digitaldrifter

Hi,

I'm just curious to know where you found a replacement CMOS battery?

Finally got my new CPU in and tossed it in there. Under continued load, touching the metal heat spreader right over the CPU it still feels pretty hot, and the fan comes on, but after about 30 minutes of various usage (Installing and running Quake 2, rebooting into DOS and running Doom, etc) it has never locked up. Seems pretty stable. I have yet to do an extended test, since I want to tear it down to swap out the CMOS battery and the display. I want to see how a small Linux distro will run on this thing. So far, it feels WAY faster than stock. Running Quake 2 it seems pretty slow, really, but I blame that on the crappy video chipset.

Can't argue with a K6-2 400 and 128mb of ram!

JimGarb, I can't remember what the model is, but I went to Radio Shack and they had one in stock. I think it was around $7.99. Hard to get at, but easy to swap in once you have access.

Digitaldrifter

I recommend trying puppy Linux on it. Seems.to be one of the smallest and easiest to load Linux versions I've used....but its been a while.