Re: Recode to Play MP3?

["Michael J. Mahon" <mjmahon@aol.com>]

mdj wrote:
> On May 23, 7:21 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
>
> > Actually, it cannot safely cache "sub-bank-switched" regions of memory
> > without "knowing" their bank-switch protocols, and, unfortunately, the
> > $C800-$CFFE region is such a sub-bank-switched region.  If it could be
> > made slot-specific, and the cache logic took the slot that originated
> > the /IOSTROBE into account, it could work, by disabling caching of the
> > extension space when switched in by certain slots.  I don't know of any
> > accelerators that go to this length.
>
>
> A lot of extra logic for a very small gain, I'd venture.

Bingo.

> > > > Indeed--but the question still hinges on how fast data can be moved
> > >
> > > > from RAM to sound RAM.  I would actually expect a "slinky"-style of
> > >
> > > > interface to the sound RAM, considering what is stored there, but I
> > > > haven't yet taken the time to research it.  (I figured someone who
> > > > knew this area well would chime in.  ;-)
> >
> > > Yes. bandwidth to sound RAM might be impeded while the DOC is running,
> > > necessitating faster Disk IO.
> >
> > The DOC bandwidth shouldn't have to be very high, but who knows?
> > Certainly, the DOC has priority for access to the sound RAM.
>
>
> I guess superficially speaking it *is* a 32 voice chip, and it seems
> reasonable that whatever bandwidth it uses while active is constant,
> regardless of the number of voices. I wish I had a IIgs hardware
> reference handy.

But certainly it must have the capability of disabling unused
oscillators, so that a mono sound could be played with just one
oscillator (I understand that one oscillator is always used for
timing, but that shouldn't be an issue).

-michael

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