Thinkpads Forum

Got different MMC-1 module at pentium mmx 166MHz. No startup, no activity/no LCD coming up. Had tried pentium mmx 266MHz module and results in boot up, cannot enter bios and pre-boot blinking cursor stage that would boot but will not. Putting back in Pentium II 266 that was originally came with this 600 works fully.

I have Pentium MMX 233 module coming in.

One weird thing about the type models on this notebook there are two labels:
One is standard 2645-A1U and other is white label pasted on says:

This system is assembled in the USA using authorized components to the referenced machine type model under the ibm authorized assembler program: IB 26455IU

frustrated: *why?* Also updated the bios as well.

Cheers, thinkpadcollection

Is this the same deal as you were posting about here: http://forum.thinkpads.com/viewtopic.php?f=6&t=117457

If I get you right here, you're trying to install a Pentium MMX CPU in a 600 that originally came with a PII CPU. Even though these share the same MMC-1 connector, I'm still of the opinion that these two CPU types are different, and will not be interchangeable. Which means that the 600 that came with MMX CPU have a different motherboard (rather some kind of hardware difference) from the 600 that came with PII CPU.

Intel Mobile Pentium MMX: http://www.thinkwiki.org/wiki/Intel_Mobile_Pentium_MMX

Intel Mobile Pentium II: http://www.thinkwiki.org/wiki/Intel_Mobile_Pentium_II

But I might get you wrong, and you might be trying to achieve something else than I think here.

This motherboard is MMC-1 and was reported by someone who was able to overclock 233 mmx to 266MHz. My board is FRU: 10L1701, is there any newest or revised FRU part number to try?

Re the other thinkpad 600 with pentium II 266:

I'll have to replace systemboard and see; board is FRU: 10L1701 is odd apparently does not like the pentium mmx. I just got the 233mmx module today, post activities reboots every time without even ever boot from hard drive.

I had tried 266mmx and 166mmx as well. Different issues.

Like I said, HMM is not *always* the bible on everything even part numbers does not exist in there and out there are many system boards without FRU stickers. I have two computer of this instances.

The HMM for this also does not say which system boards are for except for 600 (MMC-1) and 600E (MMC-2) and also are referenced by screen sizes. But the important information is "reason" behind different FRU part numbers that are not in HMM. I need that to know now to proceed.

Keep everyone updated as I go.

Cheers, thinkpadcollection.

May I ask why you are trying Pentium 1 CPU's when P2's and P3's are available and will offer far superior performance?

Temetka wrote:May I ask why you are trying Pentium 1 CPU's when P2's and P3's are available and will offer far superior performance?

I wanted an pentium mmx notebook for long time since last time I had a pentium 100 desktop. Having notebooks is more useful for older types and easier to store and includes LCD. That combination made for more fun than fussing with larger desktops and one or two displays.

Besides, I already have 3 PIII machines: pair of A21m (750 & 500MHz) and one T23 PIII 1.2GHz. Pentium notebook will finally fill the last slot of my Pentium mmx and III class legacy group. A31p is pushing the upper end, but finding last T30 would be nice.

I have been hardware expert repairer for years servicing computers and TVs.

Cheers, thinkpadcollection

I have a 390X that uses a MMC-2 P111 cpu. I also have a spare overclocked and switchable between 700 and 850 ghz MMC2 cpu.

I would sell them on in the unlikely event that anyone would be interested.

Great THinkpads though......

Motherboard FRU: 10L1708 is PII MMC-1 only. Will not work with Pentium MMX no matter what. I had to get another board with different FRU part number and that worked. Also another finding is IBM/lenovo coded the BIOS to use Pentium MMX 233mmx only and three speeds of PII of 233, 266 and 300. This really confuses the problem much more for me.

Since I still have good incompatible 600 with working PII 266 with dying LCD salvaged from junk 600E, so I will go straight to 600X at end of month instead.

Case closed.

Cheers, thinkpadcollection

There is a BIOS hack to go from MMX MMC-1 to PII MMC-1 I can't say I ever tried to go the other way.
BUT if you can go one way you can surely go the other.
I've built 600's (and 390's and 770's) all the way up to PII 400MHz with a MMC-1 CPU
I did a similar BIOS hack back in the day on 650MHz T20's to go up to 1GHz

Good that you figured it out. It took me a while to understand what you were trying to achieve here, as the usual way back in the days was to attempt an upgrade from MMX to PII. But for building a collection where you're trying to represent all generations, I can see how such a "downgrade" can make sense.

Correct, Norway Pad. I try to be clear on writing but this is not my strong suit on english (deaf).

One more thing regarding 600X there is one more curveball thrown at all of us, to have 650MHz, which cannot be upgraded from 450, 500 on other 600X's, need to do use different speedstep enabled compatible 600X motherboard that were originally came with 650MHz CPUs to work if upgrading to faster speedstep module any speed above 650MHz.

thinkpadcollection

thinkpadcollection wrote:One more thing regarding 600X there is one more curveball thrown at all of us, to have 650MHz, which cannot be upgraded from 450, 500 on other 600X's, need to do use different speedstep enabled compatible 600X motherboard that were originally came with 650MHz CPUs to work if upgrading to faster speedstep module any speed above 650MHz.

I agree, this one is a little gem. I searched for a 600X for a while before I found one that I decided was a genuine SpeedStep machine. I was for a while tempted to put in a 800MHz CPU that I have, but I realized there is nothing to gain these days, so I let it stay with the 650MHz. A great mod back in the days when every MHz counted, though.