View Full Version : Anyone recognize these extensions

November 16th, 2006, 11:27 AM
I have in excess of 100 floppies, 5.25" 360K, that apparently came from various county courthouses. They appear to be backups of a database and I'm just curious as to what software was in use.

Each disk has 6 files with the county name followed by the extension $CO, $DB, $NI, $CI, $AI, and $PI. The dates on all files are from 1986.

I've been formatting them and using them for my Dimension 68000.


November 16th, 2006, 07:56 PM
IMHO (please anyone correct me) :-&

The $'s are used by the backup/restore program to indicate that the file is part of a backup set (but not compressed) or the files are part of an install disk set. I have definitely seen this kind of thing before. You may simply have to rename the files by finding out what the $ originally was. Renaming will work unless the files are also compressed. See if you can find a "disk 1" to locate any DOS batch files that were used to restore the files ("insert disk 2", etc).

I have also seen $ in front of partially recovered files, but why would you have disk after disk of the same partially recovered files? That does not seem to be a logical assumption. I am guessing that you have a stack of install disks.

The actual extensions could be (I am making an educated guess)

$CO, $DB, $NI, $CI, $AI, and $PI
ICO, MDB, INI, PCI (?), AAI (?), and DPI (?)

Anyway, The restoring program looks up the extension using some sort of retrieval table and copies to the restore destination with the $'s replaced by the appropriate character from the lookup table.

The actual program that created the backup is unknown to me, but I bet that it's a "major" vendor install or archive tool software of the time like Norton or Symantec or Fastback or something. Looks like a late 80's - mid 90's. Back then software companies used to rename their files so that a non hacker would have to use the install program to install software onto a harddrive, and force a register step somehow.

Educated speculation.

For kicks, start up a Windows 3.1 or 3.0 system and try this from the DOS prompt:
cd \ [enter]
dir *.?CO /s [enter]

...this should output all of the files that have an extension with the last two characters of "CO." If you get a match, then you have a candidate for what the $CO is when renamed during install. Repeat with each of the $nn extensions. If you really want to be thorough repeat on different IBM PC or clone from the era of 1985-95

If you have to de-compress a file try LZH.exe if you can find a copy. THis is a pretty flexible de-compression utility of the era. newer de-compression programs would be another option.

Bill D

November 16th, 2006, 09:11 PM
I forget the URL but I know there's a web site that lists nearly every file extension in existence... so go Google. :)

November 17th, 2006, 12:43 AM
I have no idea what program it was. I strongly suspect that all the files that end in I are "index" files, the DB one is obviously the main data file and CO would be static stuff like Name, address, tele#, bla bla.

If I was betting, I would go for Dbase IV for DOS.

November 17th, 2006, 05:48 PM
Yeah, I suspect it was Dbase as well. I checked several extension databases on the web but didn't find anything conclusive.

I'm not really that intent on reading the files, just merely curious. I'll continue to use the disks for the Dimension.