Re: Software on Old Disks

["Michael J. Mahon" <mjmahon@aol.com>]

Great Hierophant wrote:
> Floppy Disks can just as easily be labeled fragile disks.  Their
> lightweight construction can make the disk easily unreadable.  Bending,
> warping, physical abuse, coming apart.  Then the media itself was not
> designed with longevity in mind.  Bit-rot is virtually inevitable, and
> can be caused or facilitated by dust, dirt, mold, extreme temperatures,
> humidity, finger oils, stratches, tears, overuse, crushed in a stack,
> electromagnetic fields, kept too long in the disk drive.  But even the
> best kept disks are not immune from time, but they seemingly have so
> little of it.

I have kept my 1980-era disks cool and dry, and have experienced
no problems with them losing data.

The only problem I _have_ seen is mold, affecting disks that were
apparently kept in a moist environment.

> The only way to buy software these days is to receive a guarantee that
> it works and was used recently.  However, with software that uses
> several disks or sides, the user may never realized that a lesser-used
> but vital side no longer works.  (Disk integrity programs may assist to
> an extent, but not if the problem has turned a 0 into a 1 or vice
> versa.)

Actually, most common bit-flipping problems will be detected by the
Apple II checksums.  There is a certain probability that _multiple_
errors will _not_ be detected, however.

-michael

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

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