🚀 go-pugleaf

On 27 Dec 1995 16:00:17 GMT, William Taylor <wwtaylor@ix.netcom.com> wrote:

>In article <4bhhpt$cg9@aladdin.iii.org.tw> Kim Monson,
>KMonson@cyberstation.net writes:
>>Intel's Zappa MB seems to only support up to 133 MHz. However, there is talk 
>>of future Pentium overdrive chips like today's 486 DX4s that run faster 
>>within the CPU, but run at the system clock rate externally. Apparently this 
>>would work in a board such as the Zappa.
>
>I'm confused. Pentium's are using a clock multiplier. It seems to me that
>all they need is the correct external clock from the motherboard: 50, 60,
>66Mhz. The cpu then takes that and multiplies it to get the correct
>internal speed. 
>
>Why can't you plug a P5/166 chip in a P5/100 board (66Mhz) and have it
>run? The only problem I can think of is the BIOS. 

The pentium needs two bits of info - the clock multiplier, and the bus speed.
A P60 has a 1x clock and a bus of 60mHz.  A P90 has a 1.5x clock and a bus of
60mHz.  A P133 has a 2x clock and a bus of 66mhz,  etc., etc.
Naturally, you could put a P166 in a P100 board and run it as anything from a
P75 to a P100, as long as the clock/bus speed jumpers were properly set.


=====================================

Tim Kelley
tkelley@ix.netcom.com