Help unzipping old zip files

[Dr H]

This brings up an "interesting" problem that has plagued me at various times.

I've seen a lot of various backup systems, of greater or lesser sophistication, come and go over the years.  Cassette tapes; big floppy disks; small floppy disks; Travan tape; DAT; RAID; external HD; SSD; etc.  We exhort people to make regular backups, multiple backups, we automate backups, etc.  And sometimes they're life-savers.  Like if a power surge or leaky sprinkler system takes out the main server, and when you bring up the new server you can pull in the overnight backups and only have lost a few hours work, if that.

But every now and then you need to pull out a backup of that spreadsheet from 2002, or the stats table from 1998.  And you find that your current backup systems aren't compatible with your previous backup systems.  Different software; software incompatible with the OS; software incompatible with the hardware; wrong hardware; existing server won't run the old hardware; hardware doesn't exist anymore; etc., etc.

This past summer I had to recover some records that were backed up on 3-1/2" floppies.  Disks could not be removed from the premises; no computer or workstation in the place had a floppy drive.  So I bought a USB floppy drive, only to discover that these are notorious for not being able to read old floppies.  Say what?  It's not like I needed the thing to make NEW floppies, for crying out loud.  Went through four different brands of USB drive before I found one that would read the floppies.  

Turns out they were PKzip files, like the OP had.  Fortunately, I found an archived copy of PKzip on the server.  Unfortunately, the files had been archived with a password.  Fortunately, I found the password written on a floppy label in the bottom of the box of disks.  Eventually recovered the files, and now they are the proud owners of a drive that will cheerfully record NEW 3-1/2" floppies, but only has about a 3-in-5 hit rate for reading OLD floppies.

This was a relatively easy case, though.  I've has backups on DAT that couldn't be read by software currently being used to do backups on DAT, because it was made with an older version.  I've had tapes that couldn't be read in a current tape drive, because the format had been changed at some point.  I've had hard drive backups that couldn't be decrypted with the current version of the same software that had been used to make the backup, albeit several years earlier.

What  a PITA.  It seems to me that backup software/technology -- among all other software/technology -- should always be as backward-compatible as possible.  What's the point of spending time meticulously archiving information if ten years later when it's needed, no one can read it?



Now, if I can just find a good way to get that 16,000 line FORTRAN program off those punched cards, and onto my laptop . . .