diff --git a/src/mame/drivers/naomi.c b/src/mame/drivers/naomi.c
index 2705c556519..29077782a33 100644
--- a/src/mame/drivers/naomi.c
+++ b/src/mame/drivers/naomi.c
@@ -26,7 +26,7 @@ TODO (general):
     - games using "m4" decryption have never successfully worked, may be
       an issue there.
 
-    - Following games doesn't boot, any attempt makes it to return to the system test mode (note these are also "m4" type games)
+    - Following games don't boot, any attempt makes it to return to the system test mode (note these are also "m4" type games)
     * Illvelo
     * Akatsuki Blitzkampf Ausf Achse
 
@@ -43,7 +43,7 @@ TODO (general):
     * Dynamic Golf
     * Inu no Osampo
 
-    - wrong JVS I/O specs, doesn't boot due of it:
+    - wrong JVS I/O specs, doesn't boot because of it:
     * Derby Owners Club II
     * Kick '4' Cash (hopper)
     * Sega Marine Fishing
@@ -51,6 +51,7 @@ TODO (general):
 
     - "com error occured between Naomi BD and I/O BD"
     * Samba de Amigo
+    * Samba de Amigo (prototype)
     * Samba de Amigo Ver. 2000
 
     - other issues:
@@ -4860,6 +4861,34 @@ ROM_START( samba )
 	ROM_LOAD( "samba-key.bin", 0, 4, CRC(e17e3603) SHA1(5611615064a93cc9d957cc4edd12c716a72cd7f2) )
 ROM_END
 
+// prototype - only works with US BIOS
+ROM_START( sambap )
+	NAOMI_BIOS
+	NAOMI_DEFAULT_EEPROM
+
+	ROM_REGION( 0x8800000, "rom_board", ROMREGION_ERASEFF)
+    ROM_LOAD( "sambaproto.ic22",0x000000, 0x0400000, CRC(ca069449) SHA1(03c2498664df187a98b335f1757979ebcf45c591) ) 
+	ROM_LOAD("mpr-22950.ic1",  0x0800000, 0x0800000, CRC(16dee15c) SHA1(b46849e492756ff406bf8956303472255fcf55a5) )
+	ROM_LOAD("mpr-22951.ic2",  0x1000000, 0x0800000, CRC(f509496f) SHA1(41281576f7d58c8ede9c0a89bfd46a98d5b97033) )
+	ROM_LOAD("mpr-22952.ic3",  0x1800000, 0x0800000, CRC(fb9b3ef0) SHA1(e9d44b673c273e97445a12186496a0594e291542) )
+	ROM_LOAD("mpr-22953.ic4",  0x2000000, 0x0800000, CRC(07207ce0) SHA1(b802bb4e78f3737a4e333f819b9a4e0249037288) )
+	ROM_LOAD("mpr-22954.ic5",  0x2800000, 0x0800000, CRC(c8e797d1) SHA1(fadbd1e24882787634229003245293ce79ba2617) )
+	ROM_LOAD("mpr-22955.ic6",  0x3000000, 0x0800000, CRC(064ef007) SHA1(8325f9aa537ce329e71dce2b588a3d4fc176c37b) )
+	ROM_LOAD("mpr-22956.ic7",  0x3800000, 0x0800000, CRC(fe8f2964) SHA1(3a33162f797cd93b7dbb313b531215e340719110) )
+	ROM_LOAD("mpr-22957.ic8",  0x4000000, 0x0800000, CRC(74842c01) SHA1(b02884925270edb66831ab502a0aa2f9430adc9f) )
+	ROM_LOAD("mpr-22958.ic9",  0x4800000, 0x0800000, CRC(b1ead447) SHA1(06b848eb7f592763768050a1ae82b4cac9499684) )
+	ROM_LOAD("mpr-22959.ic10", 0x5000000, 0x0800000, CRC(d32d7983) SHA1(86a9e5eae4598b6998f0ea578d6152e66c1a0df1) )
+	ROM_LOAD("mpr-22960.ic11", 0x5800000, 0x0800000, CRC(6c3b228e) SHA1(782c0fda106222be75b1973586c8bf78fd2186e7) )
+	ROM_LOAD("mpr-22961.ic12s",0x6000000, 0x0800000, CRC(d6d26a8d) SHA1(7d416f8ac9fbbeb9bfe217ccc8eccf1644511110) )
+	ROM_LOAD("mpr-22962.ic13s",0x6800000, 0x0800000, CRC(c2f41101) SHA1(0bf87cbffb7d6a5ab32543cef56c9759f475419a) )
+	ROM_LOAD("mpr-22963.ic14s",0x7000000, 0x0800000, CRC(a53e9919) SHA1(d81eb79bc706f85ebfbc56a9b2889ae62d629e8e) )
+	ROM_LOAD("mpr-22964.ic15s",0x7800000, 0x0800000, CRC(f581d5a3) SHA1(8cf769f5b0a48951246bb60e9cf58232bcee7bc8) )
+	ROM_LOAD("mpr-22965.ic16s",0x8000000, 0x0800000, CRC(8f7bfa8a) SHA1(19f137b1552978d232785c4408805b71835585c6) )
+
+	ROM_REGION( 4, "rom_key", 0 )
+	ROM_LOAD( "samba-key.bin", 0, 4, CRC(e17e3603) SHA1(5611615064a93cc9d957cc4edd12c716a72cd7f2) )
+ROM_END
+
 /*
 
 SYSTEMID: NAOMI
@@ -7860,6 +7889,7 @@ ROM_END
 /* 0018 */ GAME( 1999, sgtetris, naomi,    naomim2, naomi,    naomi,    ROT0, "Sega", "Sega Tetris", GAME_FLAGS )
 /* 0019 */ GAME( 1999, dybb99,   naomi,    naomim2, dybbnao,  naomi,    ROT0, "Sega", "Dynamite Baseball '99 (JPN) / World Series '99 (USA, EXP, KOR, AUS) (Rev B)", GAME_UNEMULATED_PROTECTION|GAME_FLAGS )
 /* 0020 */ GAME( 1999, samba,    naomi,    naomim2, naomi,    naomi,    ROT0, "Sega", "Samba De Amigo (JPN) (Rev B)", GAME_UNEMULATED_PROTECTION|GAME_FLAGS )
+/* 0020 */ GAME( 1999, sambap,   samba,    naomim2, naomi,    naomi,    ROT0, "Sega", "Samba De Amigo (prototype)", GAME_UNEMULATED_PROTECTION|GAME_FLAGS )
 /* 0021 */ GAME( 2000, virnbap,  virnba,   naomi,   naomi,    naomi,    ROT0, "Sega", "Virtua NBA (prototype)", GAME_FLAGS )
 /* 0021 */ GAME( 2000, virnbao,  virnba,   naomim2, naomi,    naomi,    ROT0, "Sega", "Virtua NBA (JPN, USA, EXP, KOR, AUS) (original)", GAME_FLAGS )
 /* 0021-01 */ GAME( 2000,virnba, naomi,    naomi,   naomi,    naomi,    ROT0, "Sega", "Virtua NBA (JPN, USA, EXP, KOR, AUS)", GAME_FLAGS )
diff --git a/src/mame/mame.lst b/src/mame/mame.lst
index 9cb9fe0865f..e5cd67ad801 100644
--- a/src/mame/mame.lst
+++ b/src/mame/mame.lst
@@ -4877,6 +4877,7 @@ otrigger		// 1999.11 OutTrigger
 				// 1999.12 Mars TV
 puyoda			// 1999.12 Puyo Puyo Da!
 samba			// 1999.12 Samba de Amigo (Rev B)
+sambap			// 1999.?? Samba de Amigo (prototype)
 vtennisg		// 1999.?? Virtua Tennis / Power Smash (GD-ROM)
 vtennis			// 1999.12 Virtua Tennis / Power Smash (cartridge)
 alpiltdx		// 1999.?? Airline Pilots Deluxe (Rev B)