Virtual Pen Driver

The virtual pen driver (VPENDC.VXD) handles hardware interrupts generated by the pen device. At each interrupt, the virtual pen driver organizes the raw data from the pen device and passes the organized data to the pen driver (PENC.DRV).

The virtual driver is the only component that communicates directly with the pen hardware. Therefore, the OEM developer can confine any modifications of the pen device driver to the virtual pen driver code.