This routine really had me thinking.
It really is smart.
First i thought saw a problem when A + B overflows and (B+1) = FF
But as i commented it for myself i saw that the problem i thought
i saw was that a zero was not added in that case, and 
adding a zero or not don�t change the result, as we all know... :)

I post my comments for anyone interested:

>    movfw       B
>    addwf       A,F            ;if A + B sets carry,
>
>    movfw       B + 1  ;and B+1 = FF
>    skpnc                      ;then
>      incfsz    B + 1,W        ;W here becomes 00
>        addwf   A + 1,F        ;and this add to A+1 is skipped,
                                ;so A+1 is neither read nor updated !
        ;It does not matter, as it is zero we would add.        :)
        ;The good thing is that carry is saved, as we jump over addwf,
        ;so we always have a relevant carry into next section below!
>
>    movfw       B + 2  ;The same in this section...
>    skpnc    btfsc
>      incfsz    B + 2,W
>        addwf   A + 2,F
>
>    movfw       B + 3  ;and this etc..
>    skpnc
>      incfsz    B + 3,W
>        addwf   A + 3,F
>
>dwayne

Regards
/Morgan


        Morgan Olsson                   ph  +46(0)414 70741
        MORGANS REGLERTEKNIK            fax +46(0)414 70331
        H�LLEK�S           (in A-Z letters: "HALLEKAS")
        SE-277 35 KIVIK, SWEDEN               mrt@iname.com
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