Scott Dattalo wrote:

> multiply the two 4-bit variables s and t:
>
>     swapf   s,f    ;place s in the upper nibble
>     clrw           ;result will go here
>     clrc           ;
>     btfsc   t,0
>      addwf  s,w
>     rrf     s,f
>
>     btfsc   t,1
>      addwf  s,w
>     rrf     s,f
   <etc..>

This is incorrect!
perhaps this is better:

    swapf   s,w
    clrc
    clrf    result

    btfsc   t,0
     addwf  result,f
    rrf     result,f

    btfsc   t,1
     addwf  result,f
    rrf     result,f

    btfsc   t,2
     addwf  result,f
    rrf     result,f

    btfsc   t,3
     addwf  result,f
    rrf     result,f


Scott