IOS_Exclusive_Access

mov ah,  Type      ; type of handle
mov eax, DriveNum  ; drive to lock
mov ebx, Handle    ; handle of thread or VM
mov ecx, LockFlag  ; nonzero to lock, zero to unlock
VxDCall IOS_Exclusive_Access
jc error

Locks a given drive for exclusive access from one virtual machine (VM). Works only with DCB_type_floppy devices.

• Carry flag is set on error.

DriveNum

Zero-based drive number of drive to lock or unlock.

Type

Type of handle specified by Handle. Can be IOSEA_LOCK_THREAD to indicate thread handle or 0 to indicate VM handle.

Handle

Handle of thread or VM to receive exclusive access as specified by the Type parameter.

LockFlag

Can be nonzero to lock the given drive, or zero to unlock it.