diff --git a/src/mame/drivers/hh_hmcs40.cpp b/src/mame/drivers/hh_hmcs40.cpp
index 783f16be481..3bc28b5a538 100644
--- a/src/mame/drivers/hh_hmcs40.cpp
+++ b/src/mame/drivers/hh_hmcs40.cpp
@@ -77,6 +77,7 @@
   - Though very uncommon when compared to games with LED/lamp display,
     some games may manipulate VFD plate brightness by strobing it longer,
     eg. cgalaxn when the player ship explodes.
+  - bzaxxon 3D effect is difficult to simulate
 
 ***************************************************************************/
 
diff --git a/src/mame/drivers/hh_ucom4.cpp b/src/mame/drivers/hh_ucom4.cpp
index fb866b8b410..d3411390e2b 100644
--- a/src/mame/drivers/hh_ucom4.cpp
+++ b/src/mame/drivers/hh_ucom4.cpp
@@ -47,6 +47,7 @@
  @209     uPD553C  1982, Tomy Caveman (TN-12)
  @258     uPD553C  1984, Tomy Alien Chase (TN-16)
 
+ *511     uPD557LC?1980, Gakken Game Robot 9/Mego Fabulous Fred
  @512     uPD557LC 1980, Castle Toy Tactix
 
  @060     uPD650C  1979, Mattel Computer Gin