Would anyone know how the chipset (Southbridge now called Platform Controller Hub) works with respect to a user mode application and the OS communications ? For example what is the role of the chipset when a user is typing text in a program like Microsoft Word 2007/2010 under a Windows OS environment ? Does all data entered by the user go through the chipset ? I understand that all keystrokes orginate from the keyboard is forwarded by the keyboard controller then channeled through the chipset (Southbridge now called Platform Controller Hub) then to the OS which in turn forwards to the application correct ? But does the forwarding by the OS again pass through the Platform Controller Hub chipset before it reaches the application ? I believe it does but anyone please correct me if I am mistaken. Are there any good resources books or datasheet or sites which provide an explanation on how this interaction between applications and the OS and the chipset actually works ?