Enhanced input using packet switching over a PS/2 or other interface

摘要

A designated byte of a PS/2 packet is used for data not recognized by a conventional PS/2 port driver. Each packet byte received by the conventional port driver is read by an Interrupt Service Routine (ISR) of a filter driver. If a received packet contains an unrecognized data type, that data is extracted. The filter driver converts the byte containing the data to 0000 0000. The port driver provides the all-zero byte to a higher level driver for processing into a subsequent data structure. A Service Callback Routine of the filter driver receives that data structure from the higher level driver. Depending upon the type of unrecognized data extracted by the ISR, that data is then either inserted into the data structure or passed independently of that data structure to a user level application.