On Sun, 12 Sep 1999, leo van Loon wrote:

> I want to drive a piëzo sounder on pin GP4 and GP5 in counter phase with
> leds driven on GP0 to GP2
> How can I toggle these two pins with minimum code?

GPn == 1<<n

MASK	equ	GP0 | GP2 | GP4 | GP5

    movlw   GP0 | GP4
    movwf   GPIO

loop
    movlw   MASK
    xorwf   GPIO,f
    goto    loop

This code toggles the LEDs and the piezo. But I'm not sure if that's what
you're asking.

MASK	equ	GP4 | GP5

    movlw   GP4
    movwf   GPIO

loop
    movlw   MASK
    xorwf   GPIO,f
    goto    loop

This code toggles the piezo without affecting the LEDs. 

Scott