SaveRestore Hardware

This service is available for .PMI files that use the PMI language to 
define SetMode sections. 

The PM driver performs its own Save and Restore of the state and is not 
dependent on the service.  The bvhsvga.dll uses the Save and Restore State 
service to save and restore OS/2 full screen sessions; in case of a 
partial restore, bvhsvga.dll reissues the mode set and restores the 
important video attributes. 

The SaveRestore Hardware service is based on the PMI sequence for the 
SetMode; all of the ports that are programmed by the SetMode section for 
the current mode will be saved and restored. When saving a mode, the 
VIDEOPMI interpreter parses the command list of the SetMode section. 

BOUTB commands are converted into BINB commands. The VIDEOPMI executes the 
newly constructed section in order to capture register values and converts 
all of the commands back into their original SetMode format. The command 
list is then ready for a subsequent RestoreState call and is returned to 
the user. 

This approach has some limitations, mainly for adapters that employ double 
and higher indirection levels in register addressing; for example, the 
WDc24.