diff --git a/src/mame/drivers/deco_ld.c b/src/mame/drivers/deco_ld.c
index 921d7e0fa1e..9353f030964 100644
--- a/src/mame/drivers/deco_ld.c
+++ b/src/mame/drivers/deco_ld.c
@@ -465,7 +465,7 @@ ROM_START( cobra )
 	ROM_LOAD( "au09",   0xa000, 0x2000, CRC(74e93394) SHA1(7a1470cf2008b1bef8d950939b758707297b3655) )
 
 	DISK_REGION( "laserdisc" )
-	DISK_IMAGE_READONLY( "cobra", 0, NO_DUMP )
+	DISK_IMAGE_READONLY( "cobra", 0, SHA1(8390498294aca97a5d1769032e7b115d1a42f5d3) )
 ROM_END
 
 // Bega's Battle
diff --git a/src/mame/drivers/gottlieb.c b/src/mame/drivers/gottlieb.c
index df6370b4a4a..400b86d083d 100644
--- a/src/mame/drivers/gottlieb.c
+++ b/src/mame/drivers/gottlieb.c
@@ -2426,7 +2426,7 @@ ROM_START( cobram3 )
 	ROM_LOAD( "bh06",   0xc000, 0x2000, CRC(ab6c7cf1) SHA1(3625f2e00a333552036bff99af25edeac5915d78) )
 
 	DISK_REGION( "laserdisc" )
-	DISK_IMAGE_READONLY( "cobracom", 0, NO_DUMP )
+	DISK_IMAGE_READONLY( "cobracom", 0, SHA1(8390498294aca97a5d1769032e7b115d1a42f5d3) )
 ROM_END
 
 
@@ -2605,7 +2605,7 @@ GAME( 1984, curvebal, 0,        gottlieb1, curvebal, romtiles, ROT270, "Mylstar"
 /* games using rev 2 sound board */
 GAME( 1983, screwloo, 0,        screwloo,  screwloo, screwloo, ROT0,   "Mylstar", "Screw Loose (prototype)", 0 )
 GAME( 1983, mach3,    0,        g2laser,   mach3,    romtiles, ROT0,   "Mylstar", "M.A.C.H. 3", 0 )
-GAME( 1984, cobram3,  0,        g2laser,   mach3,    romtiles, ROT0,   "Data East","Cobra Command (M.A.C.H. 3 hardware)", GAME_NOT_WORKING )
+GAME( 1984, cobram3,  0,        g2laser,   mach3,    romtiles, ROT0,   "Data East","Cobra Command (M.A.C.H. 3 hardware)", 0 )
 GAME( 1984, usvsthem, 0,        g2laser,   usvsthem, romtiles, ROT0,   "Mylstar", "Us vs. Them", 0 )
 GAME( 1984, 3stooges, 0,        gottlieb2, 3stooges, stooges,  ROT0,   "Mylstar", "The Three Stooges In Brides Is Brides", 0 )
 GAME( 1984, vidvince, 0,        gottlieb2, vidvince, vidvince, ROT0,   "Mylstar", "Video Vince and the Game Factory (prototype)", GAME_IMPERFECT_GRAPHICS ) // sprite wrapping issues