Recovering DC600A and DC6525 data cartridges...

Over one thousand DC600A and DC6525 data cartridges dating back to the 1980s were sent to us for analysis. The data was no longer accessible and contained secret information regarding military hardware.

The media was written in a range of operating systems including CPIO and SYTOS. SYTOS encrypts the headers and those written in version 3.11 and earlier encrypted the data using a table look-up, which took days to decipher. For each character we were required to work out the translation.

Getting the original software to process these tapes was not possible hence the only way to extract the files was to write a utility. CPIO is a fairly easy format to work with and these ran through very quickly. We found many erased tapes. The operating system energizes a full width erase bar which erases across the whole of the 18 recorded data tracks. Since the data is serpentine this meant that once we got past the first erased section, we could read up to PEOD then back to PBOT. Then this was repeated for further erased sections, so we ended up with up to 9 sections of data.

Of the tapes sent to us, we managed to recover 98% finally copying the data to HDD.