INT 2F U - DRIVER.SYS support - ADD NEW BLOCK DEVICE
AX = 0801h
DS:DI -> drive data table (see AX=0803h)
Notes:  moves down internal list of drive data tables, copying and modifying
the drive description flags word for tables referencing same physical
drive
data table appended to chain of tables
supported by DR-DOS 5.0

See also: 2F0803

2F0801 - DRIVER.SYS support - ADD NEW BLOCK DEVICE