diff --git a/src/mame/drivers/nmk16.cpp b/src/mame/drivers/nmk16.cpp
index 3d2b78fb778.4558f538bf1 100644
--- a/src/mame/drivers/nmk16.cpp
+++ b/src/mame/drivers/nmk16.cpp

@@ -1105,6 +1105,44 @@ void nmk16_state::gunnail_map(address_map &map)

}

+void nmk16_state::gunnailb_map(address_map &map)

+ map(0x000000, 0x07ffff).rom();

+ map(0x080002, 0x080003).portr('IN1');

+ map(0x08000a, 0x08000b).portr('DSW2');

+ map(0x080015, 0x080015).w(FUNC(nmk16_state::nmk_flipscreen_w));

+ map(0x080019, 0x080019).w(FUNC(nmk16_state::nmk_tilebank_w));

+ map(0x088000, 0x0887ff).ram().w(m_palette, FUNC(palette_device::write16)).share('palette');

+ map(0x08c000, 0x08c1ff).writeonly().share('scrollram');

+ map(0x08c200, 0x08c3ff).writeonly().share('scrollramy');

+ map(0x090000, 0x093fff).ram().w(FUNC(nmk16_state::nmk_bgvideoram_w<0>)).share('nmk_bgvideoram0');

+ map(0x09c000, 0x09cfff).mirror(0x001000).ram().w(FUNC(nmk16_state::nmk_txvideoram_w)).share('nmk_txvideoram');

+ // map(0x194000, 0x194000)

+

+void nmk16_state::gunnailb_sound_map(address_map &map)

+ map(0x0000, 0x7fff).rom();

+ map(0xc000, 0xdfff).ram();

+

+void nmk16_state::gunnailb_sound_io_map(address_map &map)

+ map.global_mask(0xff);

+ //map(0x00, 0x00).w(FUNC(nmk16_state::macross2_sound_bank_w));

+ //map(0x02, 0x03).rw('ymsnd', FUNC(ym2203_device::read), FUNC(ym2203_device::write));

+ //map(0x04, 0x04).rw(m_oki[0], FUNC(okim6295_device::read), FUNC(okim6295_device::write));

+ //map(0x06, 0x06).r(m_soundlatch, FUNC(generic_latch_8_device::read));

+

{

@@ -4628,6 +4666,27 @@ void nmk16_state::gunnail(machine_config &config)

}

+void nmk16_state::gunnailb(machine_config &config)

+ gunnail(config);

+ m_maincpu->set_addrmap(AS_PROGRAM, &nmk16_state::gunnailb_map);

+ GENERIC_LATCH_8(config, m_soundlatch);

+ Z80(config, m_audiocpu, 4000000); /* 4 MHz ? */

+ m_audiocpu->set_addrmap(AS_PROGRAM, &nmk16_state::gunnailb_sound_map);

+ m_audiocpu->set_addrmap(AS_IO, &nmk16_state::gunnailb_sound_io_map);

+ subdevice<ym2203_device>('ymsnd')->irq_handler().set_inputline(m_audiocpu, 0);

+ OKIM6295(config.replace(), m_oki[0], XTAL(16'000'000)/4, okim6295_device::PIN7_LOW); // no OKI banking

+

+ config.device_remove('oki2');

+

void nmk16_state::macross2(machine_config &config)

/* basic machine hardware */

@@ -5147,6 +5206,12 @@ void nmk16_state::init_bjtwin()

}

+void nmk16_state::init_gunnailb()

+ decode_gfx();

+}

/* NO NMK004, it has a PIC instead */

READ16_MEMBER(nmk16_state::vandykeb_r){ return 0x0000; }

@@ -6605,6 +6670,28 @@ ROM_START( gunnail )

ROM_LOAD( '10_82s123.u96', 0x0200, 0x0020, CRC(c60103c8) SHA1(dfb05b704bb5e1f75f5aaa4fa36e8ddcc905f8b6) ) /* unknown */

+// bootleg board labeled 'GT ELEKTRONIK 16.04.93' with only 1 OKI and no NMK custom chips. Only sprites and bgtile ROMs are identical to the original.

+ ROM_REGION( 0x80000, 'maincpu', 0 ) /* 68000 code */

+ ROM_LOAD16_BYTE( '27c020.6d', 0x00000, 0x40000, CRC(b9566c46) SHA1(dcecec0d401cdf8054b4b7a5dedee62332d92002) )

+ ROM_LOAD16_BYTE( '27c020.6e', 0x00001, 0x40000, CRC(6ba7c54d) SHA1(3932b96d2f1f541f8679524de3bb8867aded9f83) )

+ ROM_REGION( 0x20000, 'audiocpu', 0 )

+ ROM_LOAD( '27c010.3b', 0x00000, 0x20000, CRC(6e0a5df0) SHA1(616b7c7aaf52a9a55b63c60717c1866940635cd4) )

+ ROM_REGION( 0x020000, 'fgtile', 0 )

+ ROM_LOAD( '27c010.5g', 0x000000, 0x020000, CRC(6d2ca620) SHA1(6ed3b9987d1740f36235e33bdd66867c24f93f7e) ) /* 8x8 tiles */

+ ROM_REGION( 0x200000, 'bgtile', 0 )

+ ROM_LOAD( '27c160.k10', 0x000000, 0x200000, CRC(062100a9) SHA1(c7e81656b8112c161d3e9be3edf001da97721727) ) /* 16x16 tiles, 1st and 2nd half identical */

+ ROM_REGION( 0x200000, 'sprites', 0 )

+ ROM_LOAD16_WORD_SWAP( '27c160.a9', 0x000000, 0x200000, CRC(d49169b3) SHA1(565ff7725dd6ace79b55706114132d8d867e81a9) ) /* Sprites */

+ ROM_REGION( 0x040000, 'oki1', 0 ) /* OKIM6295 samples */

+ ROM_LOAD( '27c020.1c', 0x00000, 0x40000, CRC(c5f7c0d9) SHA1(dea090ee535edb4e9167078f6e6e5fe4e544625a) )

+

ROM_START( macross2 ) /* Title screen shows Kanji characters & Macross II */

ROM_REGION( 0x80000, 'maincpu', 0 ) /* 68000 code */

ROM_LOAD16_WORD_SWAP( 'mcrs2j.3', 0x00000, 0x80000, CRC(36a618fe) SHA1(56fdb2bcb4a39888cfbaf9692d66335524a6ac0c) )

@@ -8373,7 +8460,8 @@ GAME( 1991, hachamfp, hachamf, hachamf, hachamfp, nmk16_state, empty

GAME( 1992, macross, 0, macross, macross, nmk16_state, init_nmk, ROT270, 'Banpresto', 'Super Spacefortress Macross / Chou-Jikuu Yousai Macross', 0 )

GAME( 1993, gunnail, 0, gunnail, gunnail, nmk16_state, init_nmk, ROT270, 'NMK / Tecmo', 'GunNail (28th May. 1992)', 0 ) // Tecmo is displayed only when set to Japan

-// a 1992 version of Gunnail exists, see https://www.youtube.com/watch?v=tf15Wz0zUiA 3:10

+GAME( 1992, gunnailb, gunnail, gunnailb, gunnail, nmk16_state, init_gunnailb, ROT270, 'bootleg', 'GunNail (bootleg)', MACHINE_NO_SOUND ) // different sound hardware not hooked up

+// a 1992 version of Gunnail exists, see https://www.youtube.com/watch?v=tf15Wz0zUiA 3:10; is this bootleg version 'gunnailb'?

GAME( 1993, macross2, 0, macross2, macross2, nmk16_state, init_banked_audiocpu, ROT0, 'Banpresto', 'Super Spacefortress Macross II / Chou-Jikuu Yousai Macross II', MACHINE_NO_COCKTAIL )

GAME( 1993, macross2g, macross2, macross2, macross2, nmk16_state, init_banked_audiocpu, ROT0, 'Banpresto', 'Super Spacefortress Macross II / Chou-Jikuu Yousai Macross II (GAMEST review build)', MACHINE_NO_COCKTAIL ) // Service switch pauses game

diff --git a/src/mame/includes/nmk16.h b/src/mame/includes/nmk16.h
index 6865d96b6c2.1ba5719f9ef 100644
--- a/src/mame/includes/nmk16.h
+++ b/src/mame/includes/nmk16.h

void twinactn(machine_config &config);

void gunnail(machine_config &config);

void hachamf(machine_config &config);

void bjtwin(machine_config &config);

void init_banked_audiocpu();

void init_grdnstrmau();

void init_spec2k();

void init_grdnstrmg();

void firehawk_map(address_map &map);

void gunnail_map(address_map &map);

+ void gunnailb_sound_map(address_map &map);

void hachamf_map(address_map &map);

void macross2_sound_io_map(address_map &map);

diff --git a/src/mame/mame.lst b/src/mame/mame.lst
index 46f8d50323d.1876c87d9f6 100644
--- a/src/mame/mame.lst
+++ b/src/mame/mame.lst

@@ -30646,6 +30646,7 @@ grdnstrmj // (c) 1998 (Japan)

grdnstrmv // (c) 1998 Apples Industries license

+gunnailb // bootleg

hachamfa // (c) 1991 NMK