PE3M Small Form Factor PC
Internal Jumpers
Page 23
Jumpers
The processor board used in the PE3M PC is largely free of selection jumpers. Most settings are controlled from
the BIOS, and stored in the CMOS memory.
Only two jumpers are significant. One jumper block is used on the board, to clear the CMOS memory. This
would become necessary if the BIOS settings, which are held in the CMOS memory, became corrupted. The
second selects the front side bus (FSB) speed to match the CPU and the memory.
CMOS Clear
To clear the CMOS memory, first switch off the PC power, then locate the 3-pin header labelled
‘JP4’
on the processor board between the IDE2 connector and the battery. Remove the link shorting pins 1
and 2, and place it on pins 2 and 3 for about five seconds. Remove the link and replace it in its original
position. The CMOS has now been cleared and the BIOS will be reset to the default settings.
Please remember that the board will not function correctly if the CMOS clear link is left in the "Clear"
position.
Having no link fitted is an invalid option.
Set FSB Speed
This will have been set to suit the CPU fitted to the motherboard. If the CPU is changed, check the
position of the jumper on the 3-pin header labelled
‘JP3’
. This is located between the CPU and the
edge of the board adjacent to the power supply unit.
Three possible options exist:
For Automatic Selection of the FSB speed, link pins 1 and 2.
For CPUs with 100 (400) MHz FSB, set the jumper to link pins 2 and 3.
For CPUs with 133 (533) MHz FSB do not fit the jumper.
Automatic Selection (link 1-2) is the default option.