> 1.Why doesn't this work?

I'm sure it does work exactly as you wrote it.  If that isn't what you
intended, then I can't say because you never said what you wanted it to do.

<soapbox>
*****  COMMENT YOUR CODE, *&#$&@ !  *****
</soapbox>

>         list p=16f876
>         include "P16f876.inc"
> ;...............................
> tmp equ  0x21
> ;...............................
>         org 0x00
>         goto start
> ;...............................
> start
>          movlw 0x1
>          movwf tmp
>          nop
>    if tmp  = = 1

Note that this is always false since TMP = 21h.

>          call sub1
>    else
>          call sub2
>    endif
>          nop

Note that this will fall thru to SUB1, which will do a RETURN and cause a
stack underflow.

> ;...............................
> sub1
>          nop
>          return
> ;..............................
> sub2
>          nop
>          return
>          end


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, olin@embedinc.com, http://www.embedinc.com

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