Code:
TRISB = 0       'Assign all pins as output pins.

loop:

        PORTB = 255     'Set all PortB pins HIGH. Or, PORTB = %11111111.
        PAUSE 250
        PORTB = 0       'Set all PortB pins LOW.  Or, PORTB = %00000000.
        PAUSE 250
        GOTO loop
        
        
'        "HIGH" Command can be used for an individual pin.
'            Ex: HIGH PORTB.0    'This will set PORTB.0 high.
'                LOW  PORTB.0    'This will set PORTB.0 Low.

end