VFBACKUP_Lock_All_Ports

include vfbackup.inc

VxDCall VFBACKUP_Lock_All_Ports
 

The floppy disk controller arbitration service VFBACKUP_Lock_All_Ports is used to prevent all access to the native floppy disk controller. The function VFBACKUP_Lock_NEC might not completely disable all I/O ports, particularly when the I/O ports are not trapped (such as direct I/O). This function calls Enable_Local_Trapping for each floppy disk I/O port to ensure that all I/Os are routed to the VFBACKUP I/O port handler. Next, a special flag is set that effectively turns the VFBACKUP I/O port handler into a "no op" (which does nothing). This service is useful when you want to disable FDC I/O activity caused by direct I/O. A typical usage might be to disable the BIOS's INT 08 floppy disk motor timeout function.

This function can only be called after VFBACKUP_Lock_NEC is called. The effect of this function is turned off when VFBACKUP_Unlock_NEC is called.