Re: A86: BG v1.0 grayscale converter is out !


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Re: A86: BG v1.0 grayscale converter is out !




Bryan Rabeler wrote:

> Ti86ROM@aol.com wrote:
>
> > In a message dated 6/2/98 7:40:36 PM EST, yarin@acc.umu.se writes:
> >
> > >
> > >  ?!?! The part in Daedalus which makes the game slow is (mainly) all
> > >  mathematical calculations, especially multiplications. Instead of
> > > calculating
> > >  $36*$2B with a 8 bit multiplication routine, it would be quite much faster
> > > to
> > >  just fetch the result from a HUGE table. If the table is to support every
> > >  $xx*$xx multiplcation, it would have to have 256x256/2 entries (since a*b
> > >  = b*a), each entry taking 2 bytes. Thus 64k is needed.
> > >
> > 256 * 256 / 2 = 32k, not 64k
>
> True.  He said 256*256/2 entires, and each entry is 2 bytes.  So 256*256/2*2 =
> 64k.

Also, you have a*a and there are no duplicates to elimate for those.  So you must
add 256/2 or 128 entries to the total.  So 256*256/2 + 256/2 = 32896 entires.  Each
is 2 bytes so you have 65792 bytes or 64.25k.

--
Bryan Rabeler <brabeler@ticalc.org>
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