Sony PCV-RX270DS - Manual (Page 77)

System Board 63
Configuration Jumpers
There is one user-configurable jumper for CMOS Clear. The other two
jumpers are reserved (do not change).
The computer ships with CMOS Clear in the Normal position. Do not
change the position of this jumper unless directed by a technical support
person.
OM04588.VSD
CMOS Clear Clear
2-3
Normal
1-2
= default jumper
CMOS CLR
1
3
2
Reserved (do not change)