On Thu, 27 Jul 2017 02:08:25 -0700 (PDT), Uncle Monster
wrote:

I recall seeing some years ago an interface for hooking old mainframe reel to reel data tape drives to a PC.
There were SCSI connected drives for 9 track tape but most used
differential SCSI. You could get a differential SCSI card but it was
unusual. They were really aimed at AS/400s. The other issue was
software to support them. IBM did make a PS/2 machine that ran DOS VSE
tho. That had a 360/370 interface card that would run almost anything
that would run on a mainframe.
I bet there are less than a dozen of them running today.