Re: 65020 CPU? Look this...

[email@DELETE_THIS.luddite.no-ip.com (Simon Williams)]

Michael J. Mahon <mjmahon@aol.com> wrote:

> Simon Williams wrote:
> > Michael J. Mahon <mjmahon@aol.com> wrote:
> > 
> > 
> >>(BTW,
> >>I'm working on a synthesizer version of DAC522--one that could be
> >>an eight-voice synthesizer on an AppleCrate!  More soon.)
> > 
> > 
> > !!!!!!!
> > 
> > That would be exactly the incentive needed to turn my closetful of IIes
> > into a NadaNet... 
> 
> Ha!  I knew that would hook you, Simon!  ;-)
> 
> Actually, you made me think about how I would adapt DAC522 to the
> AppleCrate, and another e-friend, Patrick, got me back on track
> thinking about the details last week.

Okay, that's my good deed for the day!

> I found that if I'm willing to use more RAM for the DAC, I can
> create a synthesizer that plays a sample at any pitch, and with
> an arbitrary envelope (table-defined).  If the sample/envelope
> information is sufficiently compact, more than one "voice" can
> co-reside in memory.

That creates some _very_ interesting possibilities...

> Only one voice per machine can sound at a time, but that's where
> the 8-processor AppleCrate comes in.  ;-)

What about audio output? Will this make use of the cassette out port, or
do you have something more exotic in mind?

> I've also done an experiment that demonstrates that the eight
> AppleCrate machines, with their separate clock oscillators, stay
> synchronized within 22 parts per million, or, put another way,
> if all eight machines are started in sync, after 46 seconds, they
> are still within 1 millisecond of being in sync.

Close enough for Rock & Roll! (and then some)

> Allowing for the usual variations, and assuming 50 ppm, that means
> that a system that can re-sync every second or so, would only have
> 50 cycles of dispersion coming from clock variations.  This means
> that re-synchronization could be guaranteed with only a 50-cycle
> delay!  (Of course, if they are running different programs, then
> the conditionals in the program will create additional timing
> dispersion, unless limited by programming techniques.)
> 
> -michael
> 
> New Applesoft BASIC interface for NadaNet networking!
> Home page:  http://members.aol.com/MJMahon/

Anything else we should know about... perpetual motion machine? cold
fusion Apple II power supply? ;-)

-s

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