Hi Michel

Your problem is portb is configured as an output. You then try to move
portb to w and xor it with b'01000010'. That's why you get both leds on.
There is a much simpler way to do this any way. From your first call alum:
 (this asumes the leds are active high)

repeat
                btfsc   porta,0         ;is ra = 0.....
                goto    rb6on           ;
rb1on
                clrf            portb           ;yes
                bsf             portb,1         ;turn on rb1
                goto    repeat
rb6on
                clrf            portb           ;no
                bsf             portb,6         ;turn on rb6
                goto    repeat
                end

This should work, though you would normally debounce the switch by waiting
5ms after the test to check that it is still in the same position.

Regards,

Stewart Pye
At 07:52 7/05/99 +0200, Michel Mermin wrote:
>Hi
>
>I'm a beginners with the pic 16F84 and I've got a problem. With a switch
>connected to RA0, I'm trying to switch on a led connected to RB1 and
>switch off another one connected to RB6 for a switch position ans switch
>Off RB1 and siwtch on rb6 for the other position.
>
>The case where RB1 is on and RB6 if off is ok, but the other case the 2
>leds are on with a voltage of 2v5 instead on 5v.
>
>
> title  "MM1"
>;
>;  fait clignoter PB1
>;
>  LIST P=16F84
>  errorlevel 0,-305
>  INCLUDE "P16F84.inc"
>
>;  Registers
> __CONFIG _CP_OFF & _WDT_OFF & _XT_OSC & _PWRTE_ON
>
>;  Mainline of PROG16
>
>temp  equ 1
>
> org  0
>Debut
> clrf PORTB
> bsf STATUS,RP0
> movlw b'00000000'
> movwf TRISB
> movlw 0xFF
> movwf TRISA
> bcf STATUS,RP0
> call  Alum
;********
>
>Repeat movf PORTA,w
> andlw b'00000001'
> btfss STATUS,Z
> goto ZNUL
> call Etein
> goto  Repeat
>ZNUL call  Alum
> goto Repeat
>
>Alum    movlw b'00000010'
> movwf PORTB
> return
>
>Etein movf PORTB,w
> xorlw b'01000010'
> movwf PORTB
> return
> end
>