diff --git a/src/mame/drivers/comebaby.c b/src/mame/drivers/comebaby.c
index 32b9a5ce928..8409c9d34b8 100644
--- a/src/mame/drivers/comebaby.c
+++ b/src/mame/drivers/comebaby.c
@@ -1,6 +1,9 @@
 /* Come On Baby
   (c) 2000 ExPotato Co. Ltd (Excellent Potato)
 
+TODO:
+can't be emulated without proper mb bios
+
   There also appears to be a sequel which may be running on the same hardware
   Come On Baby - Ballympic Heroes!  (c) 2001
 
diff --git a/src/mame/drivers/igspc.c b/src/mame/drivers/igspc.c
index bccb243edf2..11914e6f3ba 100644
--- a/src/mame/drivers/igspc.c
+++ b/src/mame/drivers/igspc.c
@@ -2,6 +2,9 @@
 
  IGS PC based hardware
 
+TODO:
+can't be emulated without proper mb bios
+
  4 boards
     1x NV440 gfx card
     1x sound card
diff --git a/src/mame/drivers/quakeat.c b/src/mame/drivers/quakeat.c
index 3b562f5c160..31d537943c9 100644
--- a/src/mame/drivers/quakeat.c
+++ b/src/mame/drivers/quakeat.c
@@ -6,7 +6,8 @@
 
  I've also seen CDs of this for sale, so maybe there should be a CD too, for the music?
 
-
+TODO:
+can't be emulated without proper mb bios
 
  -- set info
 
diff --git a/src/mame/drivers/tokyocop.c b/src/mame/drivers/tokyocop.c
index c1cf13815f8..7d0fbae301b 100644
--- a/src/mame/drivers/tokyocop.c
+++ b/src/mame/drivers/tokyocop.c
@@ -1,5 +1,8 @@
 /* Tokyo Cop
 
+TODO:
+can't be emulated without proper mb bios
+
 Italian Version
 
 PC based hardware