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

["mdj" <mdj.mdj@gmail.com>]

Michael J. Mahon wrote:

> I agree.  And part of the problem is that you may need to read
> the disk with quarter-track resolution.  It is, unfortunately,
> impossible to recognize what "valid data" is, so the only compression
> that can safely be done is to fractional track data that is read
> as nearly identical to adjacent reads.
>
> And there is still a need to represent "soft" bits that were
> written as "0" strings but are read as "random" data.

Very true - I was considering how well the data might compress from a
storage perspective.

> 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.

> Yep, that's the level of analysis required to capture "what's on
> the disk".

I think it'll have to stay in the 'too hard' basket for now