Dell Dimension C521 - Manual (Page 43)

Jumper Settings
The jumper locations are shown below.
1 fan connector
(FAN_CPU1) 2 processor socket
(CPU) 3 memory module connectors
(DIMM_1, DIMM_2, DIMM_3,
DIMM_4)
4 power connector
(PW_12V_A1) 5 power connector
(POWER1) 6 SATA drive connectors (SATA0,
SATA1)
7 front-panel connector
(FRONTPANEL) 8 CMOS reset
(RTCRST) 9 battery socket (BT1)
10 internal USB (USB1) 11 PCI Express x16
connector (SLOT1)
12 PCI Express x1 connector
(SLOT2)
13 PCI connector (SLOT3) 14 password jumper
(PSWD)
15 floppy drive connector (FLOPPY1)
Jumper Setting Description
PSWD Password features are enabled (default setting).
Password features are disabled.
RTCRST The real-time clock has not been reset.