Actually, plenty of people had access to UNIX-like systems. There was XENIX, for example, described by some histories as "the most widely installed base of any Unix distribution" of its time.
XENIX is too often forgotten, as is the fact that the Unix world had its "archiver wars", too. In this case it was tar versus cpio, with the POSIX standardization effort settling on "pax", the pun in whose name is reportedly not a coincidence.
XENIX is too often forgotten, as is the fact that the Unix world had its "archiver wars", too. In this case it was tar versus cpio, with the POSIX standardization effort settling on "pax", the pun in whose name is reportedly not a coincidence.