Andy wrote:
>I wrote this "multiply by 255" code:
>
> > >         MOVF    B,W
> > >         MOVWF   PRODUCT_HI
> > >         SUBLW   0
> > >         MOVWF   PRODUCT_LO
> > >         DECF    PRODUCT_HI
>
>and David Duffy <PICLIST@MITVMA.MIT.EDU> replied:
>
> > I've done it like this
> >
> >          decf    B,w
> >          movwf   x_int_h
> >          clrf    x_int_l
> >
> > Does that make sense?
>
>     David:
>
>     It makes sense, but it's not correct.
>
>     What you've calculated is 256 * (B - 1), which is not the same
>     as 255 * B.

Doh!  What a dummy I'd be!
Oh well, I put in your code to fix that (my) bug but am still having
problems when A gets lower than 06h. Maybe I've got an error in
the division routine. The required equation is (B*255)/A
I still haven't found a suitable simple 16 by 8 in 16 routine.
Regards...

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