File Xfer between mainframe and unix via token ring

[Phil Scott]

We have a client running AT&T UNIX on an Everex 386 acting as a file
server for several PC's.  The network os is AT&T stargroup.  Everything
is wired for token ring.  The installation also has an 3090/400E running
MVS-XA.  They want to communicate between the unix system and the
mainframe.  Constraints are high-speed (no serial lines) and strongly
prefer token ring rather than run a "foreign" type of wiring.  Rabbit
and Cleo have sent him literature but his impression is it is too
expensive for what they do.  Any suggestions?