INT 21 U - DOS 4.0 internal - IFSsee Installable File System IOCTL
AH = 6Bh
AL = subfunction
00h ???
DS:SI -> Current Directory StructureThe data record used by DOS to keep track of the current directory on a drive; whether the drive is valid, network, SUBSTituted, or JOINed; and other pertinent information. See also INT 21h Function 52h.???
CL = drive (1=A:)
01h ???
DS:SI -> ???
CL = file handle???
02h ???
DS:SI -> Current Directory StructureThe data record used by DOS to keep track of the current directory on a drive; whether the drive is valid, network, SUBSTituted, or JOINed; and other pertinent information. See also INT 21h Function 52h.???
DI = ???
CX = drive (1=A:)
Return: CF set on error
AX = error code (see #01680 at INT 21/AH=59h/BX=0000h)
CF clear if successful
Notes: passed through to INT 2F/AX=112Fh with AX on top of stack
Novell DOS 7 Update 15 returns CF set/AX=0001h (invalid function)
SeeAlso: AH=6Bh"DOS 5",INT 2F/AX=112Fh