Sun Microsystems Ultra 5, Service Manual

Page: 238 / 258

C-38 Sun Ultra 5 Service Manual • February 2000
C.7.1 Serial Port Jumpers
Serial port jumpers JP3 and JP4 can be set to either RS-423 or RS-232 serial interface.
The jumpers are preset for RS-423. RS-232 is required for digital telecommunication
within the European Community. The following table identifies serial port jumper
settings. If the system is being connected to a public X.25 network, the serial-port-
mode jumper setting may need to change from RS-423 to RS-232 mode. The
following figure illustrates the JP3/JP4 jumper settings for RS-423 (default) interface.
FIGURE C-19
JP3/JP4 Jumper Settings for RS-423 Interface
To change the serial port jumper setting from RS-423 (default) to RS-232, refer to
Section 8.6.2 “Replacing the Motherboard” on page 8-18.
C.7.2 Flash PROM Jumpers
Flash PROM jumpers JP1 and JP2 are used for reprogramming specific code blocks
and remote programming of the flash PROM. The following figure illustrates the
JP1/JP2 jumper settings (default) for the flash PROM and the following table
identifies the flash PROM jumper settings. The default shunt settings of jumpers JP1
and JP2 are 1-2. Placing the shunt on pins 2 and 3 enables reprogramming of the
flash PROM.
TABLE C-16
Serial Port Jumper Settings
Jumper
Pins 1-2
Select Pins 2-3
Select
Default Jumper on Pins
JP3 RS-232 RS-423 2-3
JP4 RS-232 RS-423 2-3
1
JP3
JP4
2
3
1
2
3