INT 2F U - DOS 3+ internal - OPEN DEVICE AND SET SFT OWNER???
AX = 120Ch
SDA current SFT pointer -> SFT for file
DS = DOS DS
SS = DOS DS (must be using a DOS internal stack)
Return: ES, DI, AX destroyed
Notes:  invokes "device open" call on device driver for SFT
changes owner of last-accessed SFT to calling process if it was opened
via FCB
called by network redirectors such as MSCDEX


2F120C - DOS 3+ internal - OPEN DEVICE AND SET SFT OWNER???