diff options
Diffstat (limited to 'src/mame/seibu/metlfrzr.cpp')
-rw-r--r-- | src/mame/seibu/metlfrzr.cpp | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/src/mame/seibu/metlfrzr.cpp b/src/mame/seibu/metlfrzr.cpp new file mode 100644 index 00000000000..04b79f1aa6e --- /dev/null +++ b/src/mame/seibu/metlfrzr.cpp @@ -0,0 +1,483 @@ +// license:BSD-3-Clause +// copyright-holders:Angelo Salese +// thanks-to: David Haywood, Peter Wilhelmsen +/************************************************************************************************************************* + + Metal Freezer (c) 1989 Seibu + + driver by Angelo Salese, based off initial work by David Haywood + thanks to Peter Wilhelmsen for the decryption + + HW seems the natural evolution of Dark Mist type. + + TODO: + - A few video register bits still needs sorting out (needs HW tests perhaps?) + - Nuke legacy video code and re-do it by using tilemap system. + - sprites are ahead of 1/2 frames, needs sprite DMA fixed; + - Writes at 0xb800-0xbfff or 0x8000-0x9fff during gameplays? (Check by allowing ROM write) + - Flip screen support; + - Why service mode returns all inputs as high? And why sound test doesn't seem to function at all, both BTANBs perhaps? + +**************************************************************************************************************************/ + +#include "emu.h" +#include "t5182.h" + +#include "cpu/z80/z80.h" +#include "machine/timer.h" +#include "emupal.h" +#include "screen.h" +#include "speaker.h" + + +namespace { + +class metlfrzr_state : public driver_device +{ +public: + metlfrzr_state(const machine_config &mconfig, device_type type, const char *tag) : + driver_device(mconfig, type, tag), + m_maincpu(*this, "maincpu"), + m_decrypted_opcodes(*this, "decrypted_opcodes"), + m_work_ram(*this, "wram"), + m_vram(*this, "vram"), + m_video_regs(*this, "vregs"), + m_palette(*this, "palette"), + m_gfxdecode(*this, "gfxdecode"), + m_mainbank(*this, "mainbank") + { } + + void metlfrzr(machine_config &config); + + void init_metlfrzr(); + +protected: + virtual void machine_start() override ATTR_COLD; + virtual void machine_reset() override ATTR_COLD; + virtual void video_start() override ATTR_COLD; + +private: + void legacy_bg_draw(bitmap_ind16 &bitmap, const rectangle &cliprect); + void legacy_obj_draw(bitmap_ind16 &bitmap, const rectangle &cliprect); + + uint32_t screen_update_metlfrzr(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect); + void output_w(uint8_t data); + TIMER_DEVICE_CALLBACK_MEMBER(scanline); + void decrypted_opcodes_map(address_map &map) ATTR_COLD; + void metlfrzr_map(address_map &map) ATTR_COLD; + + required_device<cpu_device> m_maincpu; + required_shared_ptr<uint8_t> m_decrypted_opcodes; + required_shared_ptr<uint8_t> m_work_ram; + required_shared_ptr<uint8_t> m_vram; + required_shared_ptr<uint8_t> m_video_regs; + required_device<palette_device> m_palette; + required_device<gfxdecode_device> m_gfxdecode; + + required_memory_bank m_mainbank; + + uint8_t m_fg_tilebank = 0; + bool m_rowscroll_enable = false; +}; + + +void metlfrzr_state::video_start() +{ + // assumes it can make an address mask with m_vram.length() - 1 + assert(!(m_vram.length() & (m_vram.length() - 1))); + + m_fg_tilebank = 0; + m_rowscroll_enable = false; + + save_item(NAME(m_fg_tilebank)); + save_item(NAME(m_rowscroll_enable)); +} + +/* + - video regs format: + [0x06] ---- --x- used during title screen transition, unknown purpose + [0x06] ---- ---x X scrolling 8th bit + [0x15] always 0? + [0x16] always 0? + [0x17] xxxx xxxx X scrolling base value + Notice that it's currently unknown how the game is really supposed to NOT enable scrolling during gameplay. + */ +void metlfrzr_state::legacy_bg_draw(bitmap_ind16 &bitmap,const rectangle &cliprect) +{ + gfx_element *gfx = m_gfxdecode->gfx(m_fg_tilebank); + const uint16_t vram_mask = (m_vram.length() - 1) >> 1; + uint16_t x_scroll_value = m_video_regs[0x17] + ((m_video_regs[0x06] & 1) << 8); + int x_scroll_base = (x_scroll_value >> 3) * 32; + + for (int count = 0; count< 32 * 33; count++) + { + int tile_base = count; + int y = (count & 0x1f); + int x_scroll_shift; + if (y > 7 || m_rowscroll_enable == false) + { + tile_base += x_scroll_base; + x_scroll_shift = (x_scroll_value & 7); + } + else + x_scroll_shift = 0; + tile_base &= vram_mask; + int x = (count >> 5); + + const uint16_t tile = m_vram[tile_base * 2 + 0] + ((m_vram[tile_base * 2 + 1] & 0xf0) << 4); + const uint8_t color = m_vram[tile_base * 2 + 1] & 0xf; + + gfx->transpen(bitmap, cliprect, tile, color, 0, 0, x * 8 - x_scroll_shift, y * 8, 0xf); + } +} + +/* + sprite DMA: + 0xfe00-0xffff contains buffer for data to be copied. + Sprites are currently lagging (noticeable during scrolling) therefore there must be either an automatic or manual trigger. + Sprite seems to traverse from top to bottom priority-wise, other than that format is almost 1:1 with darkmist.cpp. + sprite format: + [0] tttt tttt tile number + [1] x--- ---- X 8th bit + [1] -ttt ---- tile bank + [1] ---- cccc palette number + [2] yyyy yyyy Y offset + [3] xxxx xxxx X offset +*/ +void metlfrzr_state::legacy_obj_draw(bitmap_ind16 &bitmap,const rectangle &cliprect) +{ + gfx_element *gfx_2 = m_gfxdecode->gfx(2); + gfx_element *gfx_3 = m_gfxdecode->gfx(3); + uint8_t const *const base_spriteram = m_work_ram + 0xe00; + + for (int count = 0x200 - 4; count > -1; count -= 4) + { + gfx_element *cur_gfx = base_spriteram[count + 1] & 0x40 ? gfx_3 : gfx_2; + const uint8_t tile_bank = (base_spriteram[count + 1] & 0x30) >> 4; + const uint16_t tile = base_spriteram[count] | (tile_bank << 8); + const uint8_t color = base_spriteram[count + 1] & 0xf; + int y = base_spriteram[count + 2]; + int x = base_spriteram[count + 3]; + if (BIT(base_spriteram[count + 1], 7)) + x -= 256; + + cur_gfx->transpen(bitmap, cliprect, tile, color, 0, 0, x, y, 0xf); + } +} + +uint32_t metlfrzr_state::screen_update_metlfrzr(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect) +{ + bitmap.fill(m_palette->black_pen(), cliprect); + + legacy_bg_draw(bitmap, cliprect); + legacy_obj_draw(bitmap, cliprect); + return 0; +} + +void metlfrzr_state::output_w(uint8_t data) +{ + // bit 7: flip screen + // bit 6-5: coin lockouts + // bit 4: tilemap ROM banking + // bit 3-2: z80 ROM banking + // bit 1: enabled during gameplay, rowscroll enable? + // bit 0: enabled , unknown purpose (lamp?) + // TODO: bits 1-0 might actually be sprite DMA enable mask/request + machine().bookkeeping().coin_lockout_w(1, BIT(data, 6)); + machine().bookkeeping().coin_lockout_w(0, BIT(data, 5)); + m_fg_tilebank = (data & 0x10) >> 4; + m_mainbank->set_entry((data & 0xc) >> 2); + m_rowscroll_enable = bool(BIT(data, 1)); + +// popmessage("%02x %02x",m_fg_tilebank,data & 3); +} + +void metlfrzr_state::metlfrzr_map(address_map &map) +{ + map(0x0000, 0x7fff).rom(); + map(0x8000, 0xbfff).bankr(m_mainbank); + map(0xc000, 0xcfff).ram().share(m_vram); + map(0xd000, 0xd1ff).ram().w(m_palette, FUNC(palette_device::write_indirect)).share("palette"); + map(0xd200, 0xd3ff).ram().w(m_palette, FUNC(palette_device::write_indirect_ext)).share("palette_ext"); + + map(0xd400, 0xd47f).rw("t5182", FUNC(t5182_device::sharedram_r), FUNC(t5182_device::sharedram_w)); + + map(0xd600, 0xd600).portr("P1"); + map(0xd601, 0xd601).portr("P2"); + map(0xd602, 0xd602).portr("START"); + map(0xd603, 0xd603).portr("DSW1"); + map(0xd604, 0xd604).portr("DSW2"); + map(0xd600, 0xd61f).writeonly().share(m_video_regs); + + map(0xd700, 0xd700).w(FUNC(metlfrzr_state::output_w)); + map(0xd710, 0xd710).w("t5182", FUNC(t5182_device::sound_irq_w)); + map(0xd711, 0xd711).r("t5182", FUNC(t5182_device::sharedram_semaphore_snd_r)); + // following two do swapped access compared to darkmist + map(0xd712, 0xd712).w("t5182", FUNC(t5182_device::sharedram_semaphore_main_release_w)); + map(0xd713, 0xd713).w("t5182", FUNC(t5182_device::sharedram_semaphore_main_acquire_w)); + + map(0xd800, 0xdfff).ram(); + map(0xe000, 0xefff).ram(); + map(0xf000, 0xffff).ram().share(m_work_ram); +} + +void metlfrzr_state::decrypted_opcodes_map(address_map &map) +{ + map(0x0000, 0x7fff).rom().share(m_decrypted_opcodes); + map(0x8000, 0xbfff).bankr(m_mainbank); + map(0xf000, 0xffff).ram().share(m_work_ram); // executes code at 0xf5d5 +} + + +static INPUT_PORTS_START( metlfrzr ) + PORT_START("P1") + PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_UP ) PORT_8WAY + PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN ) PORT_8WAY + PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT ) PORT_8WAY + PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_8WAY + PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_BUTTON1 ) + PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_BUTTON2 ) + PORT_BIT( 0xc0, IP_ACTIVE_LOW, IPT_UNKNOWN ) + + PORT_START("P2") + PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_UP ) PORT_8WAY PORT_COCKTAIL + PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN ) PORT_8WAY PORT_COCKTAIL + PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT ) PORT_8WAY PORT_COCKTAIL + PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_8WAY PORT_COCKTAIL + PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_BUTTON1 ) PORT_COCKTAIL + PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_COCKTAIL + PORT_BIT( 0xc0, IP_ACTIVE_LOW, IPT_UNKNOWN ) + + PORT_START("START") + PORT_DIPNAME( 0x01, 0x01, "2-0" ) + PORT_DIPSETTING( 0x01, DEF_STR( No ) ) + PORT_DIPSETTING( 0x00, DEF_STR( Yes ) ) + PORT_DIPNAME( 0x02, 0x02, "2-1" ) + PORT_DIPSETTING( 0x02, DEF_STR( No ) ) + PORT_DIPSETTING( 0x00, DEF_STR( Yes ) ) + PORT_DIPNAME( 0x04, 0x04, "2-2" ) + PORT_DIPSETTING( 0x04, DEF_STR( No ) ) + PORT_DIPSETTING( 0x00, DEF_STR( Yes ) ) + PORT_DIPNAME( 0x08, 0x08, "2-3" ) + PORT_DIPSETTING( 0x08, DEF_STR( No ) ) + PORT_DIPSETTING( 0x00, DEF_STR( Yes ) ) + PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_START1 ) + PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_START2 ) + PORT_DIPNAME( 0x40, 0x40, "2-6" ) + PORT_DIPSETTING( 0x40, DEF_STR( No ) ) + PORT_DIPSETTING( 0x00, DEF_STR( Yes ) ) + PORT_DIPNAME( 0x80, 0x80, "2-7" ) + PORT_DIPSETTING( 0x80, DEF_STR( No ) ) + PORT_DIPSETTING( 0x00, DEF_STR( Yes ) ) + + PORT_START("DSW1") + PORT_DIPNAME( 0x01, 0x00, DEF_STR( Cabinet ) ) PORT_DIPLOCATION("SW1:1") + PORT_DIPSETTING( 0x00, DEF_STR( Upright ) ) + PORT_DIPSETTING( 0x01, DEF_STR( Cocktail ) ) + PORT_SERVICE_DIPLOC( 0x02, IP_ACTIVE_LOW, "SW1:2" ) + PORT_DIPNAME( 0x04, 0x04, DEF_STR( Flip_Screen ) ) PORT_DIPLOCATION("SW1:3") + PORT_DIPSETTING( 0x04, DEF_STR( Off ) ) + PORT_DIPSETTING( 0x00, DEF_STR( On ) ) + PORT_DIPNAME( 0x38, 0x38, DEF_STR( Coin_A ) ) PORT_DIPLOCATION("SW1:4,5,6") + PORT_DIPSETTING( 0x00, DEF_STR( 5C_1C ) ) + PORT_DIPSETTING( 0x20, DEF_STR( 4C_1C ) ) + PORT_DIPSETTING( 0x10, DEF_STR( 3C_1C ) ) + PORT_DIPSETTING( 0x30, DEF_STR( 2C_1C ) ) + PORT_DIPSETTING( 0x38, DEF_STR( 1C_1C ) ) + PORT_DIPSETTING( 0x18, DEF_STR( 1C_2C ) ) + PORT_DIPSETTING( 0x28, DEF_STR( 1C_3C ) ) + PORT_DIPSETTING( 0x08, DEF_STR( 1C_5C ) ) + PORT_DIPNAME( 0xc0, 0xc0, DEF_STR( Coin_B ) ) PORT_DIPLOCATION("SW1:7,8") + PORT_DIPSETTING( 0x80, DEF_STR( 2C_1C ) ) + PORT_DIPSETTING( 0x00, DEF_STR( 2C_3C ) ) + PORT_DIPSETTING( 0xc0, DEF_STR( 1C_1C ) ) + PORT_DIPSETTING( 0x40, DEF_STR( 1C_2C ) ) + + PORT_START("DSW2") + PORT_DIPNAME( 0x03, 0x03, DEF_STR( Difficulty ) ) PORT_DIPLOCATION("SW2:1,2") + PORT_DIPSETTING( 0x02, "A" ) + PORT_DIPSETTING( 0x03, "B" ) + PORT_DIPSETTING( 0x01, "C" ) + PORT_DIPSETTING( 0x00, "D" ) + // service mode returns these values divided by 10 (so 02/05/10 effectively means 20k, 50k, 100k) + // TODO: check if it extends + PORT_DIPNAME( 0x0c, 0x0c, DEF_STR( Bonus_Life ) ) PORT_DIPLOCATION("SW2:3,4") + PORT_DIPSETTING( 0x08, "20k, 50k, 100k" ) + PORT_DIPSETTING( 0x0c, "30k, 80k, 150k" ) + PORT_DIPSETTING( 0x04, "50k, 100k, 200k" ) + PORT_DIPSETTING( 0x00, "100k, 200k, 400k" ) + PORT_DIPNAME( 0x30, 0x30, DEF_STR( Lives ) ) PORT_DIPLOCATION("SW2:5,6") + PORT_DIPSETTING( 0x20, "1" ) + PORT_DIPSETTING( 0x10, "2" ) + PORT_DIPSETTING( 0x30, "3" ) + PORT_DIPSETTING( 0x00, "4" ) + // disabling following enables intro / how to play screens + PORT_DIPNAME( 0x40, 0x40, DEF_STR( Level_Select ) ) PORT_DIPLOCATION("SW2:7") + PORT_DIPSETTING( 0x40, DEF_STR( Off ) ) + PORT_DIPSETTING( 0x00, DEF_STR( On ) ) + PORT_DIPNAME( 0x80, 0x00, DEF_STR( Demo_Sounds ) ) PORT_DIPLOCATION("SW2:8") + PORT_DIPSETTING( 0x80, DEF_STR( Off ) ) + PORT_DIPSETTING( 0x00, DEF_STR( On ) ) +INPUT_PORTS_END + + + +void metlfrzr_state::machine_start() +{ + m_mainbank->configure_entries(0, 4, memregion("maincpu")->base() + 0x10000, 0x4000); +} + +void metlfrzr_state::machine_reset() +{ + m_mainbank->set_entry(0); +} + + +static const gfx_layout tile_layout = +{ + 8,8, + RGN_FRAC(1,1), + 4, + { STEP4(0,4) }, + { STEP4_INV(16,1), STEP4_INV(0,1) }, + { STEP8(0,32) }, + 32*8 +}; + +static const gfx_layout sprite_layout = +{ + 16, 16, + RGN_FRAC(1, 1), + 4, + { STEP4(0,4) }, + { STEP4(0,1), STEP4(16,1), STEP4(64*8,1), STEP4(64*8+16,1) }, + { STEP16(0,32) }, + 128 * 8 +}; + + +static GFXDECODE_START(gfx_metlfrzr) + GFXDECODE_ENTRY("tiles1", 0, tile_layout, 0x100, 16) + GFXDECODE_ENTRY("tiles2", 0, tile_layout, 0x100, 16) + GFXDECODE_ENTRY("sprites1", 0, sprite_layout, 0, 16) + GFXDECODE_ENTRY("sprites2", 0, sprite_layout, 0, 16) +GFXDECODE_END + +TIMER_DEVICE_CALLBACK_MEMBER(metlfrzr_state::scanline) +{ + int scanline = param; + + if (scanline == 240) // vblank-out irq + m_maincpu->set_input_line_and_vector(0, HOLD_LINE, 0xd7); // Z80 - RST 10h + + // TODO: check this irq. + if (scanline == 0) // vblank-in irq + m_maincpu->set_input_line_and_vector(0, HOLD_LINE, 0xcf); // Z80 - RST 08h +} + +void metlfrzr_state::metlfrzr(machine_config &config) +{ + // basic machine hardware + Z80(config, m_maincpu, XTAL(12'000'000) / 2); + m_maincpu->set_addrmap(AS_PROGRAM, &metlfrzr_state::metlfrzr_map); + m_maincpu->set_addrmap(AS_OPCODES, &metlfrzr_state::decrypted_opcodes_map); + TIMER(config, "scantimer").configure_scanline(FUNC(metlfrzr_state::scanline), "screen", 0, 1); + + t5182_device &t5182(T5182(config, "t5182", XTAL(14'318'181)/4)); + t5182.ym_read_callback().set("ymsnd", FUNC(ym2151_device::read)); + t5182.ym_write_callback().set("ymsnd", FUNC(ym2151_device::write)); + + PALETTE(config, m_palette).set_format(palette_device::xBGR_444, 0x200).set_indirect_entries(256 * 2); + + GFXDECODE(config, m_gfxdecode, m_palette, gfx_metlfrzr); + + // video hardware + screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_RASTER)); + screen.set_refresh_hz(60); + screen.set_vblank_time(ATTOSECONDS_IN_USEC(0)); + screen.set_size(256, 256); + screen.set_visarea(0, 256 - 1, 16, 256 - 16 - 1); + screen.set_screen_update(FUNC(metlfrzr_state::screen_update_metlfrzr)); + screen.set_palette(m_palette); + + // sound hardware + SPEAKER(config, "mono").front_center(); + + ym2151_device &ymsnd(YM2151(config, "ymsnd", XTAL(14'318'181) / 4)); // 3.579545 MHz + ymsnd.irq_handler().set("t5182", FUNC(t5182_device::ym2151_irq_handler)); + ymsnd.add_route(0, "mono", 0.5); + ymsnd.add_route(1, "mono", 0.5); +} + + + +ROM_START(metlfrzr) + ROM_REGION(0x20000, "maincpu", 0) + ROM_LOAD("1.15j", 0x00000, 0x08000, CRC(f59b5fa2) SHA1(6033967dad5e64f45afbcb1b45c8eb79e0787afb)) + ROM_LOAD("2.14j", 0x10000, 0x10000, CRC(21ecc248) SHA1(2fccf7db73890faf7c489bfc43c88ded54d5052d)) + + ROM_REGION(0x8000, "t5182:external", 0) // Toshiba T5182 external data ROM + ROM_LOAD("3.4h", 0x0000, 0x8000, CRC(36f88e54) SHA1(5cbea56c7e547c353ae2f9256caaceb20e5e8503)) + + ROM_REGION(0x20000, "tiles1", 0) + ROM_LOAD16_BYTE("10.5a", 0x00001, 0x10000, CRC(3313e74a) SHA1(8622dfb5c013173d5bb037254f4c23b1282404e1)) + ROM_LOAD16_BYTE("12.7a", 0x00000, 0x10000, CRC(6da5fda9) SHA1(9d7b0b26598f31da589fece3535a4d1405b03fc2)) + + ROM_REGION(0x20000, "tiles2", 0) + ROM_LOAD16_BYTE("11.6a", 0x00001, 0x10000, CRC(fa6490b8) SHA1(9a4c1e09b9e8fb256fec0a5ed120fece8a12e1c8)) + ROM_LOAD16_BYTE("13.9a", 0x00000, 0x10000, CRC(a4f689ec) SHA1(e58bfede3fabf4cfca76c20aafb3e9fb604777c9)) + + ROM_REGION(0x20000, "sprites1", 0) + ROM_LOAD16_BYTE("14.13a", 0x00001, 0x10000, CRC(a9cd5225) SHA1(f3d5e29ee08fb563fdc1af3c64128f2cd2feb987)) + ROM_LOAD16_BYTE("16.11a", 0x00000, 0x10000, CRC(92f2cb49) SHA1(498021d94b0fde216207076491702af2324a2dcc)) + + ROM_REGION(0x20000, "sprites2", 0) + ROM_LOAD16_BYTE("15.12a", 0x00001, 0x10000, CRC(ce5c4c8b) SHA1(2351d66ba51e80097ce53bfd448ac24901844cda)) + ROM_LOAD16_BYTE("17.10a", 0x00000, 0x10000, CRC(3fec33f7) SHA1(af086ba30fc4521a0114da2824f5baa04d225a89)) + + ROM_REGION(0x20000, "proms", 0) + ROM_LOAD("n8s129a.7f", 0x000, 0x100, CRC(c849d60b) SHA1(0022fb71b3d777cadac7005e6156725df9bcaf90)) + ROM_LOAD("n82s135n.9c", 0x000, 0x100, CRC(7bbd52db) SHA1(b9bab5fb515579d0270aea8b992a16eeb878f242)) + + ROM_REGION(0x20000, "plds", 0) + ROM_LOAD("pld3.14h.bin", 0x000, 0x149, CRC(8183f7f0) SHA1(3cec53838120064374ecf4ebee048409c6f34081)) + ROM_LOAD("pld8.4d.bin", 0x000, 0x149, CRC(f1e35034) SHA1(527faddbf2ac905fa59ebda8ea327e6e6a7c1fb6)) +ROM_END + + + +void metlfrzr_state::init_metlfrzr() +{ + // same as seibu/airraid.cpp + uint8_t *rom = memregion("maincpu")->base(); + + for (int A = 0x0000; A < 0x8000; A++) + { + // decode the opcodes + m_decrypted_opcodes[A] = rom[A]; + + if (BIT(A, 5) && !BIT(A, 3)) + m_decrypted_opcodes[A] ^= 0x40; + + if (BIT(A, 10) && !BIT(A, 9) && BIT(A, 3)) + m_decrypted_opcodes[A] ^= 0x20; + + if ((BIT(A, 10) ^ BIT(A, 9)) && BIT(A, 1)) + m_decrypted_opcodes[A] ^= 0x02; + + if (BIT(A, 9) || !BIT(A, 5) || BIT(A, 3)) + m_decrypted_opcodes[A] = bitswap<8>(m_decrypted_opcodes[A], 7, 6, 1, 4, 3, 2, 5, 0); + + // decode the data + if (BIT(A, 5)) + rom[A] ^= 0x40; + + if (BIT(A, 9) || !BIT(A, 5)) + rom[A] = bitswap<8>(rom[A], 7, 6, 1, 4, 3, 2, 5, 0); + } +} + +} // Anonymous namespace + + +GAME( 1989, metlfrzr, 0, metlfrzr, metlfrzr, metlfrzr_state, init_metlfrzr, ROT270, "Seibu Kaihatsu", "Metal Freezer (Japan)", MACHINE_NO_COCKTAIL | MACHINE_SUPPORTS_SAVE ) |