Hi Tony,

Thanks  so much for posting the codes.
I will try it, and advice  the result later.

Regards,

Paul H.
======================
> I haven't tested this but it should work ok. It's written simply, so you
> should be able to follow the code.
>
> Contestant buttons connected from ground to PortB pins 0 - 3 with
> pullups enabled.
> Connect LEDs via 1K resistors to portB pins 4 - 7
>
>         list p=16c84,c=140    ; processor type
>
> status equ 3h
> intcon equ 0bh
> trisa equ 85h
> trisb equ 86h
> option_reg equ 81h
> t0if equ 2h
> temp equ 0ch
>
>           ; 4MHz clock
>           ; prescaler set to divide by 32
>           ; gives about 8mS delay for mnloop
>           ; you can change this to suit your requirements
>           ;
>           ; -------------
>           ; PROGRAM START
>           ; -------------
>           ;
>
>         org 0h
>
>         clrf porta
>         clrf portb
>         bsf status,rp0      ; RP 1
>         clrf trisa          ; all outputs - not used
>         movlw b'00001111'   ; 7 - 5 = LED outputs, 3 - 0 = key inputs
>         movwf trisb
>         movlw b'00000100'   ; pullups on, prescale 1:32
>         movwf option_reg
>         bcf status,rp0      ; RP0
>
>         ; maybe put a powerup delay routine here
>
> mnloop  nop             ; wait approx 8mS
>         btfss intcon,t0if
>         goto mnloop
>
>         bcf intcon,t0if ; reset timer flag
>         movf portb,w    ; read portb
>         movwf temp      ; store result
>
>         rrf temp        ; if carry clear, key #1 was pressed
>         btfc status,carry
>         goto Check2
>
>         bsf portb,4     ; contestant 1
>         goto Loop
>
> Check2  rrf temp        ; if carry clear, key #2 was pressed
>         btfsc status,carry
>         goto Check3
>
>         bsf portb,5     ; contestant 2
>         goto Loop
>
> Check3  rrf temp        ; if carry clear, key #3 was pressed
>         btfsc status,carry
>         goto Check4
>
>         bsf portb,6     ; contestant 3
>         goto Loop
>
> Check4  rrf temp        ; if carry clear, key #4 was pressed
>         btfsc status,carry
>         goto mnloop     ; no keys pressed
>
>         bsf portb,7     ; contestant 4
>
> Loop    goto Loop       ; wait here until power down
>
>
>         end
>
> PS Don't forget to disable the WDT
>
> --
> Best regards
>
> Tony
>
> 'The Engine' - Design your own programmer.
>
> http://www.picnpoke.com
> Email picnpoke@cdi.com.au
>