At 10:06 PM 2/1/00 -0800, Todd Whitesel wrote:
>> On 28 Jan 00, at 0:48, Todd Whitesel wrote:
>> > At the 150/180 processor settings, the motherboard "runs at" 50mhz
>> > according to the BIOS messages; at the 166/200 processor settings it
>> > "runs at" 75mhz.

Those numbers are just plain freaked out. AFAIK, the 50Mhz base clock was
used for 75 and 150Mhz Pentiums ("100Mhz" was actually 66 * 1.5 = 99).
75Mhz external is overclocking for a Pentium - I don't think any Pentium
CPU is supposed to get any clock higher than 66Mhz (according to Intel,
although lots of people did it). Here's the list of external clocks vs. CPU
speeds for Pentium as I recall them:

50 - 75 150
60 - 60 90 120 180
66 - 66 100(99) 133(132) 166(165) 200(198) 233(231)

(note that most all of the 66's are off by one or two Mhz)

>> Hi,
>> the 200MHz. CPU should be operated with 60MHz. external 
>> frequency, the 180MHz. version at 66MHz.

That's reversed - 200Mhz CPU should have an external clock of 66Mhz, and
180Mhz CPU should have an external clock of 60Mhz.

>Funny, I would have expected things that were even multiples, like
>180/60mhz and 200/50mhz and so on.

In this case they are - 66 * 3 = 198Mhz = 200Mhz if you're Intel (recall
the old floating point bug! :-0 )