Here's some code I posted a couple of months ago to get PWM working on a
16C74A, it should be easy to get it going on the '73a using this as a guide.

Remember to set the pins to be output pins!

;setup stuff
        movlw   b'00001111'     ;set for PWM not CCP1
        movwf   CCP1CON         ;to ccp1con for pwm channel 1
        movwf   CCP2CON         ;to ccp2con for pwm channel 2
        bsf     T2CON,2         ;turn on timer 2

;now make it work

        ;put your desired pwm value, 0-255, into w now!

        movwf   CCPR1L          ;to PWM register channel 1
        movwf   CCPR2L          ;to PWM register channel 2


This will get you started. There are other options, but start with this
and you can get to where you want to be.

Cheers,

Bob


http://www.bobblick.com/