Question about max ram on a Thinkpad 600

Hi, I just picked up a T42 by the way, thanks to the excellent information and advice on this board.

Anyways, I'm fixing up and old TP600 for my sister for university, and the specs on IBM's site say max ram is 288mb. It has 32mb onboard, and I put in 2x128 sticks in it to bring it up to 288.

In the bios (which is latest version) it reads the 288 but says only 228 is usuable, and on bootup it only says 228 is there (rounded) in the topleft corner. So it is recognizing that the ram is there (inside the bios) but not using that extra 60mb for some reason?

One person suggested it may be because my 2x128 is pc100 and the board expects pc66.

If that theory is correct, am I better off with 228mb of pc100 or should i go to pc66 to get the full 288mb?

Any other ideas?

Thanks!
Nick

 

I don't think your PC100 should cause any problems at all, except that your ram would not run any faster than PC66 ram would, as the cpu bus is the bottleneck. Could it be that some memory is reserved for video ram? Did it also subtract 60 MB before you installed the new modules?

 

Before it had the onboard 32mb, and one stick of pc66 32mb to bring it up to 64mb total, and no it didn't subtract 60 then, it read 64mb(rounded) on bootup.

And when I try to bootup with only one stick of 128mb pc100, along with the onboard 32mb pc66, it adds up fine equalling 160mb.

I have tried the above with both sticks, and they both add up properly to the 160 so its not a problem with either 128 stick they both seem to be fine.. i still think its a strange ibm bios issue.

 

Found the solution:

http://www.techsupportforum.com/showthread.php?t=64002

Appearently it does have to do with the ram being pc100, even if it is underclockable...needs to be pc66 (at least the stick in the front slot anyways, if its 128mb)