Today I found another HP-85 tape of interest - "5010-0567/2630 - CS80 HP85 DIAG TAPE". It is labeled as being in SIF format and part of the HP85 Service System. Again, the existing archived copy consists of a disk image of the tape files which is incomplete and partially corrupted.
I'm still suffering a bit of dis-belief about the problems of imaging these tapes. Setting aside the issues of physically reading the tapes, from what I've seen, tapes have been recovered by copying files to disk which somehow fails to capture some binary system data. Tapes are then "duplicated" by then copying these files from disk back to tape, resulting in incomplete copies.
Hopefully, I'm not truly understanding the process and we do have the ability to do a raw block copy from tape to image and back.
Does anyone know how the "COPY ALL" tape-to-tape function works on the 2644 terminal?
Has anyone tried a "reverse QIC" approach? If the 9825/85 "DC100" tape drives can be re-engineered to read QIC-40 tapes, can a QIC-40 drive read an HP tape? If that's the case, then it is a short step to using ftape and dd to start tape imaging.