Tempted to mark this as MACHINE_UNEMULATED_PROTECTION (nw)

src/mame/drivers/clshroad.cpp

@@ -23,6 +23,13 @@ TODO:
   text layer is not correctly emulated, fixed by initializing VRAM to 0xf0? (that layer seems unused by this game);
 - firebatl: bad sprite colors;
 - firebatl: remove ROM patch;
+- firebatl: reads $6000-$6002 and $6100 at POST, and in the range $6100-$61ff before every start 
+  of gameplay/after player dies.
+  Currently 0-filled in ROM loading:
+  - $6100 is actually OR-ed with the coinage work RAM buffer setting at $8022, 
+  - $6124 are shifted right once at PC=0x5df and stored to $82e6, which is later checked at PC=0x187 and must 
+    be $01 otherwise game goes into an infinite loop after dying (without ROM patch)
+  - (more ...)
 
 ***************************************************************************/
 
@@ -181,6 +188,7 @@ static INPUT_PORTS_START( firebatl )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_START2 )
 
 	PORT_START("DSW1")
+	// TODO: unconventional default, may or may not be related to the ROM patch + whatever lies at $6000-$7fff
 	PORT_DIPNAME( 0x7f, 0x03, DEF_STR( Lives ) )        PORT_DIPLOCATION("SW1:1,2,3,4,5,6,7")
 	PORT_DIPSETTING(    0x00, "1" )
 	PORT_DIPSETTING(    0x01, "2" )