diff --git a/src/mame/drivers/cb2001.c b/src/mame/drivers/cb2001.c
index 7f255edf730..c78f1245408 100644
--- a/src/mame/drivers/cb2001.c
+++ b/src/mame/drivers/cb2001.c
@@ -51,8 +51,8 @@ const UINT8 cb2001_decryption_table[256] = {
 //	                                         ????                ????
 	xxxx,0x8e,xxxx,xxxx,xxxx,0x49,xxxx,xxxx, xxxx,xxxx,xxxx,0x75,xxxx,xxxx,xxxx,xxxx, /* 20 */
 //	     !!!!                ????                           pppp
-	xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,0xbe,xxxx, xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx, /* 30 */
-//	                              pppp
+	xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,0xbe,xxxx, xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,0xb0,xxxx, /* 30 */
+//	                              pppp                                     ????
 	xxxx,0xea,xxxx,xxxx,xxxx,0xb0,xxxx,xxxx, xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx, /* 40 */
 //	     !!!!                gggg
 	xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx, xxxx,xxxx,xxxx,xxxx,0x78,xxxx,xxxx,xxxx, /* 50 */
@@ -60,7 +60,7 @@ const UINT8 cb2001_decryption_table[256] = {
 	xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx, xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,0xba,xxxx, /* 60 */
 //	                                                                       gggg
 	0xc3,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx, xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx, /* 70 */
-//	pppp
+//	pppp                                               ????
 	xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,0x34, xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx,xxxx, /* 80 */
 //	                                   ????
 	xxxx,xxxx,0xe9,xxxx,xxxx,xxxx,xxxx,xxxx, xxxx,xxxx,xxxx,xxxx,0xb9,xxxx,xxxx,xxxx, /* 90 */
diff --git a/src/mame/drivers/m90.c b/src/mame/drivers/m90.c
index 8688ad394b8..5a4d7a4b074 100644
--- a/src/mame/drivers/m90.c
+++ b/src/mame/drivers/m90.c
@@ -22,10 +22,6 @@ Notes:
   selection moves too fast with the clock set at 16 MHz. It's still fast at
   8 MHz, but at least it's usable.
 
-To do:
-
-- Risky Challenge / Gussun Oyoyo use a raster effect to split the screen at the line water
-
 *****************************************************************************/
 
 #include "driver.h"