Re: [PIC] Easiest way to find the inverse of a 16-bit integer

My friend Ken Mardle also suggests that John Carmack's fast inverse square
root, then squaring may be with looking at.


      Russell


On Thu, Dec 11, 2025, 1:57 PM Jesse Lackey <[email protected]>
wrote:

> Love this list!
> J
>
>
> Harold Hallikainen wrote:
> >
> >
> > On Mon, December 8, 2025 4:26 pm, RussellMc wrote:
> >> Perplexity suggests small look up table then refined by Newton Rapson
> for
> >>   rapid convergence.
> >>
> >>
> https://www.perplexity.ai/search/algorithms-for-1-x-for-16-bit-Q77Z0QO_QS
> >> WGPRQyEXlFrg
> >>
> >>
> >>
> >> Russell.
> >
> > That looks similar to the approach at
> > https://pic.hallikainen.org/techref/microchip/math/div/recip32k-ng.htm .
> >
> > Harold
> >
> >
> >
> >>
> >>
> >> On Tue, Dec 9, 2025, 12:17 PM Dwayne Reid <[email protected]>
> >> wrote:
> >>
> >>
> >>> Good day to all.
> >>>
> >>>
> >>> As part of my current project, I need to find the inverse of a 16-bit
> >>> binary integer.  That is: 1/X.
> >>>
> >>> I was going to dig out my old division routines but was thinking there
> >>> may be an easier way to go.
> >>>
> >>> Suggestion greatly appreciated.
> >>>
> >>>
> >>> Many thanks!
> >>>
> >>>
> >>> dwayne --
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