Dell OptiPlex E1 - Manual (Page 18)

Jumpers: Dell™ OptiPlex™ E1 Systems
= jumpered
= unjumpered
* One set of the speed jumper pins must have a jumper plug installed; otherwise, the system will operate at an undetermined speed.
400MHZ Internally set. Speed jumper settings no longer apply.
366MHZ Internally set. Speed jumper settings no longer apply.
333MHZ* Jumpered when the microprocessor's internal speed is 333 MHz.
300MHZ* Jumpered when the microprocessor's internal speed is 300 MHz.
266MHZ* (default) Jumpered when the microprocessor's internal speed is 266 MHz.
233MHZ* Jumpered when the microprocessor's internal speed is 233 MHz.
BIOS (default) Reserved. Do not change.
PSWD (default) The password features are enabled.
The password features are disabled.