john wrote:

"David Maynard" wrote in message
...

john wrote:


how do i switch between 66 and 100mhz bus on compaq presario 4240es PII

333

?

i believe it may be overclocked to 500 when it should be 333 at 5*66 it
maybe 500 at 5*100

this is causeing it to overheat and freeze up, i backed off to a 3
multiplier and now it works underclocked and cooler but im not sure if

its

at 200mhz or 300mhz. meanwhile i will try to rig up another fan for it

i find jumpers for multipliers of 3,4,5,6 etc but not for bus speed

There won't be FSB jumpers on a Compaq motherboard because that's set
'automatically'.

If it's overclocked, as you suspect, then they would have probably used

the

'B21 tape trick' which causes 100/66 bus select to go high saying it wants
a 100 MHz FSB. The 'simple' way was to place a piece of tape over the pin
of the Slot-1 cart but some might cut the PCB trace for a more 'rugged'
solution. Generally they'd have to do a similar mod to the Vcore processor
voltage select pins because it won't run that fast at the stock 2.0 volts.
In fact, it's rare for a P-II 333 to hit 500 under any conditions.

However, from the almost non existent documentation on the Compaq site, I
get the idea your motherboard doesn't even support 100 Mhz FSB so I doubt
it could be overclocked the way you suspect.

Why do you think it's a P-II running 500MHz?




its overheating and freezing up so i thought it maybe overclocked, since the
silk screen on the board has two columns of info for each of the jumper
settings, i suppose its just locked at 66bus and maybe the other column is
for future possibilities.

btw it is an intel BX chipset FW82443BX 1997 with AGP set

In that case it's possible to overclock because BX is the 'official' 100
MHz FSB chipset for the P-II.


i believe the fan on the power supply is too weak to cool thru the strange
bafle they have in here, also no fan on the cpu heatsink just a baffle.

Common Compaq cooling setup for those. Works great when everything is as it
was intended to be.

i
plan to add another fan and try to get it back up to 333 its only at 200 now
and yet it still seems pretty fast, anyway for 48mb ram, i also have 128mb
pc133 sdram ordered

thats another possibility in the BIOS it has fast Memory speed and slow
memory speed, is the mem running async with the fsb?

No.

i will get pc133 anyway
but i considered that 100mem may cause 100fsb but prob not

Memory does not 'cause' the FSB. That is set by the processor 100/66 select
pin, as described above.


thanx john







any ideas

thanx john