Hi folks;
     I am new to pics so please forgive me!!
Can anyone tell me why my first program does not work?
The processor is a 16c84.

pc   equ  0h
fsr  equ  2h
porta     equ  5h
portb     equ  6h
trisa     equ  85h
trisb     equ  86h
status    equ  3h
rp0  equ  5h


org  0

main:
     call init_portb          ; Initialisation of port
     call led_output     ; Output to leds
     goto main


init_portb:
     clrf portb          ;Initialise port by setting output latches
     bsf  status, rp0    ;select bank one
     movlw     0x00      ;value used to init port
     movwf     trisb          ;set port b to all outputs
return



led_output:
     movlw     0xAA
     movwf     portb
return





That's it !

All I want it to do is to switch on some led's but when it tries to output
to the port, it seems to alter the trisb!!

Please help