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Re: [Vaporware alert!] Portable Apple II Clone Concept

mdj wrote:

Michael J. Mahon wrote:



I actually went down this path for a month or two a decade ago,
and the problem with any lof the "legacy" I/O ports on a PC is
that they are relatively slow.  I found that I could not read
a bit on the parallel port more often than about 1-2 microseconds,
which wasn't good enough resolution to do it all in software.

The Disk ][ controller samples the head signal at 2MHz, so that
would be fast enough to do whatever needs to be done.



Ah. Well I  suppose that leaves stripping the Apple bus interfacing
from the IWM and interfacing to that via Parallel or some other means.
Once this is done you've got a significantly reduced data rate to deal
with. A PIC or similar could do most of the work in this regard.


Yes, that was my conclusion, too.  Disk ][ controllers are quite
plentiful, so putting one inside the interface box seemed the most
straightforward solution.

I did have some concerns about writing (I was mostly concerned with
reading).  There are lots of jitter sources in PCs that would require
some hardware solution for precisely timed write loads.

-michael

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

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