diff --git a/src/mame/mame.lst b/src/mame/mame.lst
index 1556b56d089..97bb89e572d 100644
--- a/src/mame/mame.lst
+++ b/src/mame/mame.lst
@@ -41598,6 +41598,7 @@ riotw                           // (c) 1992 Woong Bi
 @source:tecmo/tecmosys.cpp
 deroon                          // (c) 1996 Tecmo
 deroon2                         // (c) 1996 Tecmo
+deroona                         // (c) 1996 Tecmo
 tkdensho                        // (c) 1996 Tecmo
 tkdenshoa                       // (c) 1996 Tecmo
 
diff --git a/src/mame/tecmo/tecmosys.cpp b/src/mame/tecmo/tecmosys.cpp
index 8f2cb2620df..5dff5535772 100644
--- a/src/mame/tecmo/tecmosys.cpp
+++ b/src/mame/tecmo/tecmosys.cpp
@@ -536,6 +536,47 @@ ROM_START( deroon )
 	ROM_LOAD( "t501.uad1", 0x000000, 0x080000, CRC(2fbcfe27) SHA1(f25c830322423f0959a36955edb563a6150f2142) )
 ROM_END
 
+ROM_START( deroona ) // only main CPU program ROMs differ slightly from the deroon set (a routine is NOPed out at 0x711e-0x7152). Labels are original Tecmo. Low serial number.
+	ROM_REGION( 0x100000, "maincpu", 0 ) // Main Program
+	ROM_LOAD16_BYTE( "t01.upau1", 0x00000, 0x80000, CRC(7ad6c740) SHA1(51be70edf30364919c0d1da4a9bdd16bfbace213) )
+	ROM_LOAD16_BYTE( "t02.upal1", 0x00001, 0x80000, CRC(e44f4430) SHA1(8a4ff12ef3a238694c30516fd7f39ccb4625dae9) )
+
+	ROM_REGION( 0x040000, "audiocpu", 0 ) // Sound Program
+	ROM_LOAD( "t003.uz1", 0x000000, 0x040000, CRC(8bdfafa0) SHA1(c0cf3eb7a65d967958fe2aace171859b0faf7753) )
+
+	ROM_REGION( 0x2200, "cpu2", 0 ) // MCU is a 68HC11A8 with 8k ROM, 512 bytes EEPROM
+	ROM_LOAD( "deroon_68hc11a8.rom",    0x0000, 0x2000, NO_DUMP )
+	ROM_LOAD( "deroon_68hc11a8.eeprom", 0x2000, 0x0200, NO_DUMP )
+
+	ROM_REGION( 0x2000000, "sprites", ROMREGION_ERASE00 ) // Sprites (non-tile based)
+	/* all these roms need verifying, they could be half size */
+
+	ROM_LOAD32_WORD_SWAP( "t101.uah1", 0x0000000, 0x200000, CRC(74baf845) SHA1(935d2954ba227a894542be492654a2750198e1bc) )
+	ROM_LOAD32_WORD_SWAP( "t102.ual1", 0x0000002, 0x200000, CRC(1a02c4a3) SHA1(5155eeaef009fc9a9f258e3e54ca2a7f78242df5) )
+	/*                                 0x8000000, 0x400000 - no rom loaded here, these gfx are 4bpp */
+	ROM_LOAD32_WORD_SWAP( "t103.ubl1", 0x0800002, 0x400000, CRC(84e7da88) SHA1(b5c3234f33bb945cc9762b91db087153a0589cfb) )
+	/*                                 0x1000000, 0x400000 - no rom loaded here, these gfx are 4bpp */
+	ROM_LOAD32_WORD_SWAP( "t104.ucl1", 0x1000002, 0x200000, CRC(66eb611a) SHA1(64435d35677fea3c06fdb03c670f3f63ee481c02) )
+
+	ROM_REGION( 0x100000, "layer0", 0 ) // 8x8 4bpp tiles
+	ROM_LOAD( "t301.ubd1", 0x000000, 0x100000, CRC(8b026177) SHA1(3887856bdaec4d9d3669fe3bc958ef186fbe9adb) )
+
+	ROM_REGION( 0x100000, "layer1", ROMREGION_ERASE00) // 16x16 4bpp tiles
+	/* not used? */
+
+	ROM_REGION( 0x100000, "layer2", ROMREGION_ERASE00 ) // 16x16 4bpp tiles
+	ROM_LOAD( "t201.ubb1", 0x000000, 0x100000, CRC(d5a087ac) SHA1(5098160ce7719d93e3edae05f6edd317d4c61f0d) )
+
+	ROM_REGION( 0x100000, "layer3", ROMREGION_ERASE00 ) // 16x16 4bpp tiles
+	ROM_LOAD( "t202.ubc1", 0x000000, 0x100000, CRC(f051dae1) SHA1(f5677c07fe644b3838657370f0309fb09244c619) )
+
+	ROM_REGION( 0x200000, "ymz", 0 ) // YMZ280B Samples
+	ROM_LOAD( "t401.uya1", 0x000000, 0x200000, CRC(92111992) SHA1(ae27e11ae76dec0b9892ad32e1a8bf6ab11f2e6c) )
+
+	ROM_REGION( 0x80000, "oki", 0 ) // M6295 Samples
+	ROM_LOAD( "t501.uad1", 0x000000, 0x080000, CRC(2fbcfe27) SHA1(f25c830322423f0959a36955edb563a6150f2142) )
+ROM_END
+
 /*
 About the Deroon DeroDero listed below:
 
@@ -703,7 +744,7 @@ void tecmosys_state::descramble()
 void tecmosys_state::init_deroon()
 {
 	descramble();
-	prot_init(0); // machine/tecmosys.cpp
+	prot_init(0); // tecmo/tecmosys_m.cpp
 }
 
 void tecmosys_state::init_tkdensho()
@@ -718,7 +759,8 @@ void tecmosys_state::init_tkdensha()
 	prot_init(2);
 }
 
-GAME( 1995, deroon,    0,        tecmosys, tecmosys, tecmosys_state, init_deroon,     ROT0, "Tecmo", "Deroon DeroDero (earlier)",               MACHINE_IMPERFECT_GRAPHICS | MACHINE_NO_COCKTAIL | MACHINE_SUPPORTS_SAVE )
+GAME( 1995, deroon,    0,        tecmosys, tecmosys, tecmosys_state, init_deroon,     ROT0, "Tecmo", "Deroon DeroDero (earlier, set 1)",        MACHINE_IMPERFECT_GRAPHICS | MACHINE_NO_COCKTAIL | MACHINE_SUPPORTS_SAVE )
+GAME( 1996, deroona,   deroon,   tecmosys, tecmosys, tecmosys_state, init_deroon,     ROT0, "Tecmo", "Deroon DeroDero (earlier, set 2)",        MACHINE_IMPERFECT_GRAPHICS | MACHINE_NO_COCKTAIL | MACHINE_SUPPORTS_SAVE ) // some parts translated in English, attract without 'how to play'
 GAME( 1996, deroon2,   deroon,   tecmosys, tecmosys, tecmosys_state, init_deroon,     ROT0, "Tecmo", "Deroon DeroDero / Tecmo Stackers",        MACHINE_IMPERFECT_GRAPHICS | MACHINE_NO_COCKTAIL | MACHINE_SUPPORTS_SAVE ) // some parts translated in English, attract without 'how to play'
 GAME( 1996, tkdensho,  0,        tecmosys, tecmosys, tecmosys_state, init_tkdensho,   ROT0, "Tecmo", "Toukidenshou - Angel Eyes (VER. 960614)", MACHINE_IMPERFECT_GRAPHICS | MACHINE_NO_COCKTAIL | MACHINE_SUPPORTS_SAVE )
 GAME( 1996, tkdenshoa, tkdensho, tecmosys, tecmosys, tecmosys_state, init_tkdensha,   ROT0, "Tecmo", "Toukidenshou - Angel Eyes (VER. 960427)", MACHINE_IMPERFECT_GRAPHICS | MACHINE_NO_COCKTAIL | MACHINE_SUPPORTS_SAVE )