The default clock on the 12F683 is 4MHz according to the datasheet found in REG 3-1 but still better to set it and define it along with turning OFF other peripherals not used:
Code:
@ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_OFF & _BOD_OFF

OSCCON = %01100001  ' Osc 4MHz
ADCON0 = 0          ' A/D module OFF
CMCON0 = 7	    ' Analog comparators off
GPIO = %00000000    ' Turn OFF all ports
TRISIO = %00001101  ' Ports 0, 2 and 3 inputs, rest outputs (Example)

DEFINE OSC 4        ' Declare FOR PAUSE and PAUSEUS statements
But if using PBP3 then:
Code:
#CONFIG
    __CONFIG    _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_OFF & _BOD_OFF
#ENDCONFIG

OSCCON = %01100001  ' Osc 4MHz
ADCON0 = 0          ' A/D module OFF
CMCON0 = 7	    ' Analog comparators off
GPIO = %00000000    ' Turn OFF all ports
TRISIO = %00001101  ' Ports 0, 2 and 3 inputs, rest outputs (Example)

DEFINE OSC 4        ' Declare FOR PAUSE and PAUSEUS statements