Int 2F/AX=F800h/CX=4455h

AX = F800h
CX = 4455h ("DU")
DL = 45h ("E")

Return:
AL = FFh if installed
ES:BX -> ASCII signature "Universal Data Exchange"

Program: SuperStor is a disk-compression program by Addstor.

Note: Returns AX=0001h if AL is not 00h or 01h

See Also: AX=1001h - AX=F801h