Re: Archiving Apple ][e discs

[mjmahon@aol.com (Michael J. Mahon)]

Charlie wrote:

>"Rubywand" <rubywand@swbell.net> wrote in message
>406F465B.AF7F1BA4@swbell.net">news:406F465B.AF7F1BA4@swbell.net...

<snip>

>> Must be nearly a hundred postings on
>> Csa2 over the years explaining why there's NO WAY to read Apple II
>diskettes on
>> a PC without special hardware.
>
>Don't you just love it when someone does the impossible?

I sure do!  ;-)

>>      Tried DISK2FDI on our Windows PC (with a 1.2MB 5.25" drive) and it
>works
>> fine for non-protected DOS 3.3 and ProDOS 5.25" diskettes.
>>
>>      One caveat, DISK2FDI may have difficulty with a few sectors that
>read fine
>> on your real Apple II. Making a fresh copy using Disk Muncher or some
>other
>> fast whole-disk copier seems to help.
>
>I have noticed that fresh copies with Copy II+ 7.4 (Disk option) are always
>read perfectly and faster by DISK2FDI than ones copied with the old Apple
>COPYA program.  I'm not sure why.  I have many disks that have stuff on the
>back side and I use Copy II+ to transfer the data to the front side of a
>blank disk to use with DISK2FDI.

Both Disk Muncher and the Copy II Plus "disk" option write whole
tracks, which makes the intra-sector gaps clean and predictable.

Since DISC2FDI pieces track images together by matching the
read data from several passes, the absence of "noise" between
sectors helps reduce false matches/mismatches.

>I have occasionally (about 1 out of 10 disks) had DISK2FDI read a known
>good sector as bad.  Just re-reading the disk usually reads the "bad"
>sector correctly.  The registered version has an option for re-reading a
>track with a bad sector.

This is also a characteristic of the heuristic matching that the
program does.  Whole-track re-copying (but _not_ bit copying)
should generally help.

-michael

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