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Sun Enterprise 250 Server Owner's Guide

About Flash PROM Jumpers

The system uses flash PROMs to permit the reprogramming of specific code blocks that are held in non-volatile system memory, and to permit remote reprogramming of that code by an authorized system administrator over a local area network.

Three jumpers on the main logic board affect flash PROM operation. The figure below shows the jumper locations, and the table describes their function.

Figure 5-12  

Graphic

Table 5-4  

Jumper 

Shunt on  

Pins 1 + 2 Selects 

Shunt on  

Pins 2 + 3 Selects 

Default Shunt on Pins 

J2702 

Flash PROM 

Not To Be Used 

1 + 2 

J2704 

Write Protect 

Write Enable 

2 + 3 

J2804 

High Half Booting 

Normal Booting 

2 + 3 

Note -

Jumper J2704 is factory-set so that the flash PROM is write-enabled. You use the keyswitch located on the front panel to write protect the flash PROM. When the switch is set to the Locked position, the flash PROM is write-protected. When the switch is set to the Power-on position or to the Diagnostics position, the flash PROM is write-enabled. For descriptions of the various keyswitch settings, see "About the Status and Control Panel".

For descriptions of the various keyswitch settings, see "About the Status and Control Panel".

For more information about flash PROM programming, see the documentation supplied with the flash PROM update CD-ROM.