Re: Innovative Systems Floating Point Engine Rev B 1988

[dicen <google@mcarlson.com>]

On Aug 7, 4:06 am, Mike Westerfield <Mike...@aol.com> wrote:
> On Aug 7, 3:15 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
>
>
> >MikeWesterfieldwrote:
> > > On Aug 4, 7:19 am, "Yvan" <yvan_d...@gmx.net> wrote:
> > >> Hi,
>
> > >> I found a Innovative Systems Floating Point Engine Rev B 1988.
>
> > >> First, what is it? Can I use it in my IIgs? Do I need any software or
> > >> drivers? Are there any documentations anywhere?
>
> > >> Cheers
> > >> Yvan
>
> > > Hi Yvan,
>
> > > There is a software patch that allows this card to intercept and
> > > handle any calculation normally routed through the SANE numerics
> > > package. That works pretty well, but there is significant overhead--
> > > enough that some calculations are about as fast in software. (Not all,
> > > and not the more complex calculations.)
>
> > That's been my experience with math coprocessors.
>
> > Trig functions and SQR are big wins (since their software
> > implementations are so slow), but the simple ops, like add
> > and subtract, are at best a wash.
>
> > > There are also compiler directives for the ORCA languages that will
> > > bypass SANE and tap directly into the card itself. This is
> > > considerably more efficient, and works for long integer math as well
> > > as floating-point. It turned out that short integer math takes less
> > > time in software than the overhead of using the card, so the ORCA
> > > languages do not use the card for short integers.
>
> > > All in all, it's a great card if you intend to do any number-
> > > crunching, especially in software you write. Congratulations on
> > > finding one.
>
> > The problem with most math coprocessors is that they require lots of
> > overhead moving operands in and out of the card.  A DMA-based
> > coprocessor might help a lot more.
>
> > In comparisons done on a //e, I find that a math-heavy mix of operations
> > are speeded up by a math coprocessor just about as much as by an 8MHz
> > Zip Chip--with which most math coprocessors are incompatible (because
> > they use the RDY line to stall the 6502 and the Zip Chip doesn't
> > implement it).
>
> > Since the Zip Chip speeds up everything and the math coprocessor only
> > speeds up multiply, divide, and functions, the Zip Chip wins.  ;-)
>
> > I don't know whether this math coprocessor is compatible with a IIgs
> > accelerator, but that would be something to check...
>
> > -michael
>
> > AppleCrate: An Apple II "blade server"!
> > Home page:  http://members.aol.com/MJMahon/
>
> > "The wastebasket is our most important design
> > tool--and it's seriously underused."
>
> This coprocessor works fine with an accelerator card.
>
> Whether it will speed up your calculations significantly is another
> matter. It will certainly speed up simple floating-point calculations
> like +, -, * and /, but the big win is if you are doing the more
> complex calculations, like trig or other complex functions.
>
> MikeWesterfield

The man is still alive? Now the 60,000 dollar question is did John
Carmack or John Romero ever buy your software? I seam to remember
running into them at Applefest (SF) in 1988.