http://ps-2.kev009.com/pcpartnerinfo/ctstips/f5da.htm

4/10GB 4mm DAT 5.25" SCSI Tape Drive OPT PN 74G8631 / FRU PN 16G8454.
4/10GB 4mm DAT 3.5" SCSI Tape Drive OPT PN 74G8632 / FRU PN 16G8456.

These were offered for the PC Server 500, and did have a diskette, 
AFAIK. Just don't have it.

 From personal use, the 4/10 is supported by system programs on the Type 
4 (at least). It is the Connor / Seagate 4216, and is directly supported 
on many OS.