laboye

Nope. The motherboard's crystal on an A20m can only operate at speeds up to 550MHz. This means that it won't use the full power of the Pentium. It could also be a voltage problem. Pentiums take a bit more voltage that Celerons. Also, IBMs BIOS does not provide processor tuning options, especially one as old as the A20m. You may be able to get a new motherboard for a more modern A20m model, which may have the crystal you're looking for. I have sold about 5 A20ms with 650 and 700MHz processors, so I know they exist. Please provide the model-type number on the bottom of the ThinkPad. It is located on a black and white sticker above a barcode.