update: thinkpad 600 CPU support pentium 266? , not PII 266.

[thinkpadcollection]

I picked up mobile pentium 266 w/ 512K daughterboard and tried this. Would not post past intital boot up logo yet the status LEDs flashes and fan spins. Pulled cmos battery, got into ez setup but to set time and date only. Beyond that, no luck. Will report back with bios version. The thinkwiki says pentium 233 but I wondered about anyone using 266 instead?

If not, I'll grab another pentium 233 daughterboard, from ebay or anyone to sell me one would be nice from here.

update: bios is really old! 09-25-98 which is 1.05 but the bios "says" part number 97H4147 not IBET35WW?

Cheers, thinkpadcollection

[RealBlackStuff]

97H4147 is a hard disk!
IBET35WW is the name of a BIOS file.

[pkiff]

Without doing much research to refresh my memory, I recall that the Thinkpad 600 series CPU upgrades are limited by the max available CPU that was produced in the "MMC-1" form factor. I think that's a PII 400MHz, though those are pretty rare. I have one in an old 770E, which was similar in architecture to a 600.

The MMC-1 is what you mean by "daughter" card, right? If so, then make sure you get the right format! And make sure you don't get a Celeron, but get a Pentium.

For more CPU upgrade info, be sure to review The official 600 Upgrade and general information Topic thread stickied at the top of the Legacy forum.

[Norway Pad]

The maximum CPU you can put in a PII 600, 560Z, various 380/385/390 and 770E/ED laptops is the 400MHz PII MMC-1, as pkiff says. These are hard to find, so a better choice these days is the 366MHz MMC-1, with the number PMF36602002AA. I have one of these on the desk in front of me, waiting to go in my PII 600 when I sometime have to open it up.

But there is some difference between Pentium MMX and Pentium II models. Most of the above mentioned laptops are listed as available with both PII and MMX, which I have always believed requires different motherboards. These CPUs have the same MMC-1 style connector, but I assume they're simply not compatible. IIRC, the MMX maxes out at 233MHz, but if PII and MMX had been compatible, many older MMX laptops, like some 760s and older 380s, could potentially have been upgraded to 400MHz. Which I think they can't.

So I suspect that's what's going on with thinkpadcollection's 600. It's a MMX model, so the 233MHz CPU board is the fastest MMX and will work, while the 266MHz CPU board you tested is a PII. Note: I miight be wrong here, as I have never upgraded a MMX laptop.

Edit: MMX seems to go as high as 266 MHz, so your 266 can theoretically still be a MMX. So maybe your CPU is simply defective. Hard to say at this point.

[thinkpadcollection]

I'm trying to work with pentium mmx 266 instead of PII 266. And yes I know about the MMC-1 note that I did boot up but would not complete post at all, just silently as I descibed.

Cheers, thinkpadcollection

[Norway Pad]

Ok, I see now that the subject says "not PII 266". I initially recalled that the MMXs only went to 233, but they do indeed go to 266MHz.

And you're right about 'silently'. Afterwards I found this post http://forum.thinkpads.com/viewtopic.php?f=11&t=117455 which tells us exactly what happens when a MMX CPU is installed in a PII board.

[thinkpadcollection]

Updated the thinkpad 600 bios with "1 byte" hack since batteries cannot be fully charged:

http://forum.thinkpads.com/viewtopic.ph ... 14#p517914

No success with pentium mmx 266 module yet (same signs of bootup screen then sit there silently), will try a pentium mmx 233 module later in May once I have some "play" budget set aside for May. All the thinkpad 600 MMC-1 motherboards takes most of MMC-1 modules (P-mmx and PII 233, 266 and 300). Not talking about MMC-2 through.

PS: the bios name changed from 97H4147 to latest 1.22 "IBET54WW" as displayed in easy setup screen.

Cheers, thinkpadcollection