[UnLock]

This section contains the list of commands required to make the hardware 
available for the execution of the SetMode section, as well as for saving 
and restoring of the controller and video buffer. The list of commands 
should be inclusive of saving and restoring the registers modified in the 
process, with the exclusion of the unlock key register. The function can 
be made mode-sensitive by using the conditional statements that evaluate 
key mode PMI keyvariables. However, the function could be a superset of 
all required unlock commands, for as long as such a sequence is not 
counter-productive in any mode sets. 

Here is a sample .PMI file for a 9GXE S3 card: 

inb(r0, 0x3d4);               //save index
outb(0x3d4, 0x38);
outb(0x3d5, 0x48);
outb(0x3d4, 0x39);
outb(0x3d5, 0xa0);
outb(0x3d4, r0);              //restore index