INT 21 - DoubleDOS - SET/RESET KEYBOARD CONTROL FLAGS
        AH = F8h
        AL = 00h set flags for this program
           = 01h set flags for other program
        DX = keyboard control flags (see AH=E8h"DoubleDOS")
Return: DX = previous flags
Notes:  disabling Ctrl-PrtSc will allow the program to intercept the keystroke;
          disabling any of the other keystrokes disables them completely
        this function is identical to AH=E8h
SeeAlso: AH=E8h"DoubleDOS",AH=F1h"DoubleDOS",AH=F2h"DoubleDOS"
SeeAlso: AH=F3h"DoubleDOS"

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