gamecom : lostwrld works now.

hash/gamecom.xml

@@ -139,7 +139,7 @@ List of games which were planned but never finished or released.
 		</part>
 	</software>
 
-	<software name="lostwrld" supported="no">
+	<software name="lostwrld">
 		<description>The Lost World - Jurassic Park</description>
 		<year>1997</year>
 		<publisher>Tiger Electronics</publisher>

src/devices/cpu/sm8500/sm85ops.h

@@ -1033,7 +1033,12 @@ case 0x3A:  /* MOVW rr,@rr / MOV rr,(rr)+ / MOV rr,@ww / MOV rr,ww(rr) / MOV rr,
 	mem_writeword( r1, mem_readword( s2 ) );
 	switch( r2 & 0xC0 ) {
 	case 0x00:  mycycles += 11; break;
-	case 0x40:  mycycles += 16; break;
+	case 0x40:  mycycles += 16;
+	// lostwrld expects reads from videoram to return 0. It is unknown if this should happen just in this case,
+	// or all the time, or in some other special circumstance.
+		if ((s2 >= 0xc000) && (s2 <= 0xdfff))
+			mem_writeword( r1, 0 );
+		break;
 	case 0x80:  mycycles += ( ( r2 & 0x07 ) ? 18 : 14 ); break;
 	case 0xC0:  mycycles += 16; break;
 	}

src/mame/drivers/gamecom.cpp

@@ -24,12 +24,7 @@ Todo:
 Game Status:
 - Inbuilt ROM and PDA functions all work
 - Due to an irritating message, the NVRAM is commented out in the machine config
-- All carts appear to work except:
+- All carts appear to work.
-- - Lost World: freeze just after entering Stage 2 (the nest).
-- --- If you do nothing it freezes at the point where the stegasaurus
-      should turn around. So, straight away start moving to the right
-      and you can keep playing.
-- Weblink and Internet are of no use as there is nothing to connect to.
 
 ***************************************************************************/