This is part of Family API which allow to create dual-os version of program runs under OS/2 and DOS

Note: This is legacy API call. It is recommended to use 32-bit equivalent

Device Control Categories

Category	Description
1	Serial Device Control
2	Reserved
3	Screen/Video control
4	Keyboard Control
5	Printer Control
6	Light Pen Control
7	Mouse Control
8	Logical Disk Control
9	Physical Disk Control
10	Character Device Monitor Control
11	General Device Control