The old hang-on-the-wall Partner voicemail systems use an operating system called Concurrent DOS, which is one of many manifestations of Gary Kildall's CP/M (specifically, CPM-86 from Digital Research where Gary worked) that was designed to run on 8-bit systems. IBM totally ripped it off and called it DOS. Bill Gates received a license from IBM, tweaked it and called it MicroSoft DOS (it was a capital "S" in "Soft" back then) or simply MS-DOS. You know the rest of the story.
You'll find that there are two partitions, the second being the more familiar FAT type DOS partition. If you're at all PC saavy, you'll be able to figure out pretty quickly what does what.
There is an audit and recovery utility in the O/S. It does some reindexing (IDX) of the MSG (message database) files and the like, but nothing heavy duty. These utilities run each time the box starts up, so any boot problems you now have will likely be related to the aging physical drive itself.
Given that, I'd say that your time would be better spent reading
than it would trying to fix these old voicemails.
But if you're a 42-year old hack like me, use a search engine and you'll quickly find Windows utilities which will allow you to boot a Concurrent-DOS or CP/M formatted drive as an IDE slave on your home PC. You can then pull all of AT&T/Lucent's jewels for safekeeping, format a new drive and slide the jewels back on.
Drill down on the link above and you'll find format utilities that can recreate the Con-DOS C: drive partition (which will have a "partition type" byte of "DB" as opposed to the familiar "6h).
Just like the old 007MLM Merlin Mail, begin studying the drive's condition by attaching a M-F DB9 straight-through cable to the unit. Hit <CNTL>+C during boot and type "user 1" (without the quotes) at the "1C>" prompt. Any file with the CMD extension is an executable.
That should get you started. I'll meet you back at Arkham Asylum in a few minutes...
