Com base no dump hexadecimal, isso pode ser um sistema SCO OpenServer . E esta informação pode ajudar. O melhor & resposta mais realista que encontrei está no "Unix & Site do Linux Stack Exchange ”:
Connect and mount the drive on an existing SCO system or Boot the hard drive into SCO OpenServer (or SCO rescue disk if you have one) and then copy your data off via network or removable media. I realize that this is not what you were asking but may be the shortest route depending on what you have available. You may be able to find a copy of SCO on Ebay if you don't have one (finding compatible hardware may be interesting).
Get Linux to mount the SCO HTFS filesystem via these instructions.