http://pdf1.alldatasheet.com/datasheet-pdf/vi … +/datasheet.pdf
missing R149 at Pin 16 of ICS9148-60 is most likely a 200ohm pullup to 3.3V

cheapest way of gimping BX board to 66MHz speeds

AlessandroB wrote:

the only thing I have to do is weld a 10kohm smd resistor in that place?

more likely 0 or 200ohm, but first get a multimeter, set it to resistance mode and measure (on turned off computer) ICS9148-60 between
-pin 16 (our magic select signal) and pin 19 (ground)
-pin 16 (our magic select signal) and 20 (3.3V source)
-other leg of R149 and pin 19 (ground)
-other leg of R149 and 20 (3.3V source)

This will tell us what needs to be modified. This board will definitely run 100MHz, IBM simply limited cheaper version by omitting some parts.

If that's how an internal voltage divider looks like on a 100MHz FSB PII, then it's pretty self explanatory, why this motherboard can't run @ 100MHz FSB. Klamath PII BSEL is always tied to ground, hence only 66MHz FSB, while Deschutes allows 100MHz FSB only when PLL has a pull-up resistor on MB.

First of all thank you, you are all extremely professional but I see that it is something a little complex to do, for the moment my work leaves me very little time so I pause and try in August. For now I will use the 66mhz computer. As soon as I can try it I will continue this post. thanks for now.