VioQueryConsole

This is an undocumented functions of the API.

According to some public discussion [1] VioQueryConsole may return a HVIO. Since any other VIO routine will work with a hvio = 0 (with rare exceptions) this might be the reason why that function is of no value.

Looks like IBM tried to implement multiple logical fullscreen video devices (like they did with keyboard and mouse) but didn't quite get to it or didn't see any use in doing so once they defined logical video buffers.