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Re: RFC : SOME IDEAS FOR THE APPLE II FPGA'ers



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


I agree, and also doubt the real-world benefits of speeding them up
beyond, say, 20MHz.

It would be crazy to throw out the baby with the bathwater, just to
get the possibility of a 200MHz processor that no one could tell was
running that fast when actually using the system.


A 200Mhz "stalled" CPU that keeps most of the time waiting because of
some bottleneck...

The bottlenecks... let's find them and see what can we do.

We already know that most of them are in waiting for I/O--and
particularly for the user to decide what he wants to do next.

In an accelerated Apple II, either the STA or the LDA come/go to fast
ram, and the other will require a single slow Apple II cycle, so it's
throughput skyrockets to 1MegaBytes per second.. !

Actually, only the loads go to fast RAM, the stores usually go to both
fast RAM and to the bus--you never know who's listening.  ;-)


Who may be listening out of I/O space ?
(don't count the V.O.C.)

That's an example.  There are a few others.

Yes, in a sense, we are all wasting our time.

As long as we're enjoying it, it isn't wasted...


I'll try to explain that over here... :-)

;-)

-michael

Music synthesis for 8-bit Apple II's!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it is seriously underused."