diff --git a/include/bios.h b/include/bios.h
index 61d940bc..ef37fa88 100644
--- a/include/bios.h
+++ b/include/bios.h
@@ -84,6 +84,11 @@
 
 #define BIOS_KEYBOARD_FLAGS3            0x496
 #define BIOS_KEYBOARD_LEDS              0x497
+
+#define BIOS_WAIT_FLAG_POINTER          0x498
+#define BIOS_WAIT_FLAG_COUNT	        0x49c		
+#define BIOS_WAIT_FLAG_ACTIVE			0x4a0
+
 #define BIOS_PRINT_SCREEN_FLAG          0x500
 
 #define BIOS_VIDEO_SAVEPTR              0x4a8