"It turns out they were images of the tape records written by a Cedar Mesa program called the Archivist. Luckily, when the 9-track tapes were transferred to 8mm tapes, a file called rosetta.tar containing the Archivist source code plus some documentation was included on each tape. Once I obtained a copy of rosetta.tar I was able to write a program that “dearchived” the tape records, recreating a set of file directories."
