Tape Drives for XENIX Systems

[bobey at alberta.UUCP]

Is anyone aware of an open reel (not cassette) tape drive capable
of handling tapes with large block sizes under XENIX? We are running
SCO XENIX SysV 2.0.6 on a Sperry PC/IT. 

Right now this system is equipped with an Overland Data TC-50M
9 track controller and an IBEX PCT-1000 drive. Everything works fine
except there is a 16K block size limitation (stated in the ODI manual)
and we would like to read tapes with larger blocks. ODI claims the 
limitation is due to XENIX while Sperry claims the limitation is in
the ODI device driver. Without the device driver source, there is 
no way to check who is right. Interestingly, the same system running 
MS-DOS can handle block sizes up to 64K! Can anybody help?