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 (bit set enables, cleared disables)
bit 0: menu
bit 1: exchange
bit 2: entire keyboard enable/disable
bit 3: Ctrl-C
bit 4: Ctrl-PrtSc
bit 5: Alt/Erase
bit 6: Ctrl-Break
bit 7: Ctrl-NumLock
bit 8: shift-PrtSc
bit 9-13: undefined
bit 14: cancel key (clear keyboard buffer)
bit 15: suspend key
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
identical to AH=E8h
SeeAlso: AH=F1h"DoubleDOS",AH=F2h"DoubleDOS"

See also: 21E8

21F8 - DoubleDOS - SET/RESET KEYBOARD CONTROL FLAGS