This call opens the mouse device for the current session.
MouOpen
DriverName (PSZ) - input
The name of the device driver must be included in the CONFIG.SYS file at system start-up time. Applications that use the default pointer draw device driver supplied by the system must push a double-word of 0s in place of an address.
DriverName has a different definition when the caller is the Base Video Subsystem (BVS). In this case the selector portion of the far address is zero. The offset portion is non-zero and contains a display configuration number (sequentially numbered where 1 is the first display configuration). The MouOpen call issued by BVS is executed on the VioSetMode path. Using the display configuration number passed on the MouOpen call, the Base Mouse Subsystem can detect a change in display configurations. This form of the MouOpen call is not recommended for applications. Applications should either push the far address of an ASCIIZ pointer draw device driver name or push two words of zeros.
MouOpen initializes the Mouse functions to a known state. The application may have to issue additional mouse functions to establish the environment it desires. For example, after the MouOpen, the collision area is defined to be the size of the entire display. Therefore, to get the pointer to be displayed, the application must issue a MouDrawPtr to remove the collision area.
The state of the mouse after the first MouOpen is:
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