enter_protected_mode
|| PRESENT(enter_protected_mode)
ANDMISSING(enter_protected_mode, exit_attribute_mode);
if (enter_protected_mode)
TurnOn(A_PROTECT, enter_protected_mode);
if (enter_protected_mode)
TurnOn(A_PROTECT, enter_protected_mode);
CHECK_SGR(8, enter_protected_mode);