diff options
Diffstat (limited to 'trunk/src/mame/drivers/offtwall.c')
-rw-r--r-- | trunk/src/mame/drivers/offtwall.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/trunk/src/mame/drivers/offtwall.c b/trunk/src/mame/drivers/offtwall.c new file mode 100644 index 00000000000..96a7425464d --- /dev/null +++ b/trunk/src/mame/drivers/offtwall.c @@ -0,0 +1,528 @@ +/*************************************************************************** + + Atari "Round" hardware + + driver by Aaron Giles + + Games supported: + * Off the Wall (1991) [2 sets] + + Known bugs: + * none at this time + +**************************************************************************** + + Memory map (TBA) + +***************************************************************************/ + + +#include "emu.h" +#include "cpu/m68000/m68000.h" +#include "audio/atarijsa.h" +#include "video/atarimo.h" +#include "includes/offtwall.h" + + + +/************************************* + * + * Interrupt handling + * + *************************************/ + +static void update_interrupts(running_machine &machine) +{ + offtwall_state *state = machine.driver_data<offtwall_state>(); + cputag_set_input_line(machine, "maincpu", 4, state->m_scanline_int_state ? ASSERT_LINE : CLEAR_LINE); + cputag_set_input_line(machine, "maincpu", 6, state->m_sound_int_state ? ASSERT_LINE : CLEAR_LINE); +} + + + +/************************************* + * + * Initialization + * + *************************************/ + +static MACHINE_START( offtwall ) +{ + atarigen_init(machine); +} + + +static MACHINE_RESET( offtwall ) +{ + offtwall_state *state = machine.driver_data<offtwall_state>(); + + atarigen_eeprom_reset(state); + atarigen_interrupt_reset(state, update_interrupts); + atarivc_reset(*machine.primary_screen, state->m_atarivc_eof_data, 1); + atarijsa_reset(); +} + + + +/************************************* + * + * Video controller access + * + *************************************/ + +static READ16_HANDLER( offtwall_atarivc_r ) +{ + return atarivc_r(*space->machine().primary_screen, offset); +} + + +static WRITE16_HANDLER( offtwall_atarivc_w ) +{ + atarivc_w(*space->machine().primary_screen, offset, data, mem_mask); +} + + + +/************************************* + * + * I/O handling + * + *************************************/ + +static READ16_HANDLER( special_port3_r ) +{ + offtwall_state *state = space->machine().driver_data<offtwall_state>(); + int result = input_port_read(space->machine(), "260010"); + if (state->m_cpu_to_sound_ready) result ^= 0x0020; + return result; +} + + +static WRITE16_HANDLER( io_latch_w ) +{ + /* lower byte */ + if (ACCESSING_BITS_0_7) + { + /* bit 4 resets the sound CPU */ + cputag_set_input_line(space->machine(), "jsa", INPUT_LINE_RESET, (data & 0x10) ? CLEAR_LINE : ASSERT_LINE); + if (!(data & 0x10)) atarijsa_reset(); + } + + logerror("sound control = %04X\n", data); +} + + + +/************************************* + * + * SLOOP workarounds + * + *************************************/ + + +/*------------------------------------------------------------------------- + + Bankswitching + + Like the slapstic, the SoS bankswitches memory using A13 and A14. + Unlike the slapstic, the exact addresses to trigger the bankswitch + are unknown. + + Fortunately, Off the Wall uses a common routine for the important + bankswitching. The playfield data is stored in the banked area of + ROM, and by comparing the playfields to a real system, a mechanism + to bankswitch at the appropriate time was discovered. Fortunately, + it's really basic. + + OtW looks up the address to read playfield data from a table which + is 58 words long. Word 0 assumes the bank is 0, word 1 assumes the + bank is 1, etc. So we just trigger off of the table read and cause + the bank to switch then. + + In addition, there is code which checksums longs from $40000 down to + $3e000. The code wants that checksum to be $aaaa5555, but there is + no obvious way for this to happen. To work around this, we watch for + the final read from $3e000 and tweak the value such that the checksum + will come out the $aaaa5555 magically. + +-------------------------------------------------------------------------*/ + + + +static READ16_HANDLER( bankswitch_r ) +{ + offtwall_state *state = space->machine().driver_data<offtwall_state>(); + + /* this is the table lookup; the bank is determined by the address that was requested */ + state->m_bank_offset = (offset & 3) * 0x1000; + logerror("Bankswitch index %d -> %04X\n", offset, state->m_bank_offset); + + return state->m_bankswitch_base[offset]; +} + + +static READ16_HANDLER( bankrom_r ) +{ + offtwall_state *state = space->machine().driver_data<offtwall_state>(); + + /* this is the banked ROM read */ + logerror("%06X: %04X\n", cpu_get_previouspc(&space->device()), offset); + + /* if the values are $3e000 or $3e002 are being read by code just below the + ROM bank area, we need to return the correct value to give the proper checksum */ + if ((offset == 0x3000 || offset == 0x3001) && cpu_get_previouspc(&space->device()) > 0x37000) + { + UINT32 checksum = (space->read_word(0x3fd210) << 16) | space->read_word(0x3fd212); + UINT32 us = 0xaaaa5555 - checksum; + if (offset == 0x3001) + return us & 0xffff; + else + return us >> 16; + } + + return state->m_bankrom_base[(state->m_bank_offset + offset) & 0x3fff]; +} + + + +/*------------------------------------------------------------------------- + + Sprite Cache + + Somewhere in the code, if all the hardware tests are met properly, + some additional dummy sprites are added to the sprite cache before + they are copied to sprite RAM. The sprite RAM copy routine computes + the total width of all sprites as they are copied and if the total + width is less than or equal to 38, it adds a "HARDWARE ERROR" sprite + to the end. + + Here we detect the read of the sprite count from within the copy + routine, and add some dummy sprites to the cache ourself if there + isn't enough total width. + +-------------------------------------------------------------------------*/ + + +static READ16_HANDLER( spritecache_count_r ) +{ + offtwall_state *state = space->machine().driver_data<offtwall_state>(); + int prevpc = cpu_get_previouspc(&space->device()); + + /* if this read is coming from $99f8 or $9992, it's in the sprite copy loop */ + if (prevpc == 0x99f8 || prevpc == 0x9992) + { + UINT16 *data = &state->m_spritecache_count[-0x100]; + int oldword = state->m_spritecache_count[0]; + int count = oldword >> 8; + int i, width = 0; + + /* compute the current total width */ + for (i = 0; i < count; i++) + width += 1 + ((data[i * 4 + 1] >> 4) & 7); + + /* if we're less than 39, keep adding dummy sprites until we hit it */ + if (width <= 38) + { + while (width <= 38) + { + data[count * 4 + 0] = (42 * 8) << 7; + data[count * 4 + 1] = ((30 * 8) << 7) | (7 << 4); + data[count * 4 + 2] = 0; + width += 8; + count++; + } + + /* update the final count in memory */ + state->m_spritecache_count[0] = (count << 8) | (oldword & 0xff); + } + } + + /* and then read the data */ + return state->m_spritecache_count[offset]; +} + + + +/*------------------------------------------------------------------------- + + Unknown Verify + + In several places, the value 1 is stored to the byte at $3fdf1e. A + fairly complex subroutine is called, and then $3fdf1e is checked to + see if it was set to zero. If it was, "HARDWARE ERROR" is displayed. + + To avoid this, we just return 1 when this value is read within the + range of PCs where it is tested. + +-------------------------------------------------------------------------*/ + + + +static READ16_HANDLER( unknown_verify_r ) +{ + offtwall_state *state = space->machine().driver_data<offtwall_state>(); + int prevpc = cpu_get_previouspc(&space->device()); + if (prevpc < 0x5c5e || prevpc > 0xc432) + return state->m_unknown_verify_base[offset]; + else + return state->m_unknown_verify_base[offset] | 0x100; +} + + + +/************************************* + * + * Main CPU memory handlers + * + *************************************/ + +static ADDRESS_MAP_START( main_map, AS_PROGRAM, 16 ) + AM_RANGE(0x000000, 0x037fff) AM_ROM + AM_RANGE(0x038000, 0x03ffff) AM_READ(bankrom_r) AM_REGION("maincpu", 0x38000) AM_BASE_MEMBER(offtwall_state, m_bankrom_base) + AM_RANGE(0x120000, 0x120fff) AM_READWRITE(atarigen_eeprom_r, atarigen_eeprom_w) AM_SHARE("eeprom") + AM_RANGE(0x260000, 0x260001) AM_READ_PORT("260000") + AM_RANGE(0x260002, 0x260003) AM_READ_PORT("260002") + AM_RANGE(0x260010, 0x260011) AM_READ(special_port3_r) + AM_RANGE(0x260012, 0x260013) AM_READ_PORT("260012") + AM_RANGE(0x260020, 0x260021) AM_READ_PORT("260020") + AM_RANGE(0x260022, 0x260023) AM_READ_PORT("260022") + AM_RANGE(0x260024, 0x260025) AM_READ_PORT("260024") + AM_RANGE(0x260030, 0x260031) AM_READ(atarigen_sound_r) + AM_RANGE(0x260040, 0x260041) AM_WRITE(atarigen_sound_w) + AM_RANGE(0x260050, 0x260051) AM_WRITE(io_latch_w) + AM_RANGE(0x260060, 0x260061) AM_WRITE(atarigen_eeprom_enable_w) + AM_RANGE(0x2a0000, 0x2a0001) AM_WRITE(watchdog_reset16_w) + AM_RANGE(0x3e0000, 0x3e0fff) AM_RAM_WRITE(atarigen_666_paletteram_w) AM_BASE_GENERIC(paletteram) + AM_RANGE(0x3effc0, 0x3effff) AM_READWRITE(offtwall_atarivc_r, offtwall_atarivc_w) AM_BASE_MEMBER(offtwall_state, m_atarivc_data) + AM_RANGE(0x3f4000, 0x3f5eff) AM_RAM_WRITE(atarigen_playfield_latched_msb_w) AM_BASE_MEMBER(offtwall_state, m_playfield) + AM_RANGE(0x3f5f00, 0x3f5f7f) AM_RAM AM_BASE_MEMBER(offtwall_state, m_atarivc_eof_data) + AM_RANGE(0x3f5f80, 0x3f5fff) AM_READWRITE(atarimo_0_slipram_r, atarimo_0_slipram_w) + AM_RANGE(0x3f6000, 0x3f7fff) AM_RAM_WRITE(atarigen_playfield_upper_w) AM_BASE_MEMBER(offtwall_state, m_playfield_upper) + AM_RANGE(0x3f8000, 0x3fcfff) AM_RAM + AM_RANGE(0x3fd000, 0x3fd7ff) AM_READWRITE(atarimo_0_spriteram_r, atarimo_0_spriteram_w) + AM_RANGE(0x3fd800, 0x3fffff) AM_RAM +ADDRESS_MAP_END + + + +/************************************* + * + * Port definitions + * + *************************************/ + +static INPUT_PORTS_START( offtwall ) + PORT_START("260000") + PORT_BIT( 0x0001, IP_ACTIVE_LOW, IPT_BUTTON4 ) PORT_PLAYER(2) + PORT_BIT( 0x0002, IP_ACTIVE_LOW, IPT_BUTTON1 ) PORT_PLAYER(2) + PORT_BIT( 0x0004, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(2) + PORT_BIT( 0x0008, IP_ACTIVE_LOW, IPT_BUTTON3 ) PORT_PLAYER(2) + PORT_BIT( 0x0010, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_PLAYER(2) + PORT_BIT( 0x0020, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT ) PORT_PLAYER(2) + PORT_BIT( 0x0040, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN ) PORT_PLAYER(2) + PORT_BIT( 0x0080, IP_ACTIVE_LOW, IPT_JOYSTICK_UP ) PORT_PLAYER(2) + PORT_BIT( 0x0100, IP_ACTIVE_LOW, IPT_BUTTON4 ) PORT_PLAYER(1) + PORT_BIT( 0x0200, IP_ACTIVE_LOW, IPT_BUTTON1 ) PORT_PLAYER(1) + PORT_BIT( 0x0400, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(1) + PORT_BIT( 0x0800, IP_ACTIVE_LOW, IPT_BUTTON3 ) PORT_PLAYER(1) + PORT_BIT( 0x1000, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_PLAYER(1) + PORT_BIT( 0x2000, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT ) PORT_PLAYER(1) + PORT_BIT( 0x4000, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN ) PORT_PLAYER(1) + PORT_BIT( 0x8000, IP_ACTIVE_LOW, IPT_JOYSTICK_UP ) PORT_PLAYER(1) + + PORT_START("260002") + PORT_BIT( 0x00ff, IP_ACTIVE_LOW, IPT_UNUSED ) + PORT_BIT( 0x0100, IP_ACTIVE_LOW, IPT_BUTTON4 ) PORT_PLAYER(3) + PORT_BIT( 0x0200, IP_ACTIVE_LOW, IPT_BUTTON1 ) PORT_PLAYER(3) + PORT_BIT( 0x0400, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(3) + PORT_BIT( 0x0800, IP_ACTIVE_LOW, IPT_BUTTON3 ) PORT_PLAYER(3) + PORT_BIT( 0x1000, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_PLAYER(3) + PORT_BIT( 0x2000, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT ) PORT_PLAYER(3) + PORT_BIT( 0x4000, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN ) PORT_PLAYER(3) + PORT_BIT( 0x8000, IP_ACTIVE_LOW, IPT_JOYSTICK_UP ) PORT_PLAYER(3) + + PORT_START("260010") + PORT_BIT( 0x0001, IP_ACTIVE_LOW, IPT_UNUSED ) + PORT_DIPNAME( 0x0002, 0x0000, DEF_STR( Controls ) ) + PORT_DIPSETTING( 0x0000, "Whirly-gigs" ) /* this is official Atari terminology! */ + PORT_DIPSETTING( 0x0002, "Joysticks" ) + PORT_BIT( 0x0004, IP_ACTIVE_LOW, IPT_UNUSED ) /* tested at a454 */ + PORT_BIT( 0x0008, IP_ACTIVE_LOW, IPT_UNUSED ) /* tested at a466 */ + PORT_BIT( 0x0010, IP_ACTIVE_LOW, IPT_UNUSED ) + PORT_BIT( 0x0020, IP_ACTIVE_LOW, IPT_UNUSED ) /* tested before writing to 260040 */ + PORT_SERVICE( 0x0040, IP_ACTIVE_LOW ) + PORT_BIT( 0x0080, IP_ACTIVE_LOW, IPT_VBLANK ) + PORT_BIT( 0xff00, IP_ACTIVE_LOW, IPT_UNUSED ) + + PORT_START("260012") + PORT_BIT( 0xffff, IP_ACTIVE_LOW, IPT_UNUSED ) + + PORT_START("260020") + PORT_BIT( 0xff, 0, IPT_DIAL_V ) PORT_SENSITIVITY(50) PORT_KEYDELTA(10) PORT_PLAYER(1) + PORT_BIT( 0xff00, IP_ACTIVE_LOW, IPT_UNUSED ) + + PORT_START("260022") + PORT_BIT( 0xff, 0, IPT_DIAL ) PORT_SENSITIVITY(50) PORT_KEYDELTA(10) PORT_PLAYER(2) + PORT_BIT( 0xff00, IP_ACTIVE_LOW, IPT_UNUSED ) + + PORT_START("260024") + PORT_BIT( 0xff, 0, IPT_DIAL_V ) PORT_SENSITIVITY(50) PORT_KEYDELTA(10) PORT_REVERSE PORT_PLAYER(3) + PORT_BIT( 0xff00, IP_ACTIVE_LOW, IPT_UNUSED ) + + PORT_INCLUDE( atarijsa_iii ) /* audio board port */ +INPUT_PORTS_END + + + +/************************************* + * + * Graphics definitions + * + *************************************/ + +static const gfx_layout pfmolayout = +{ + 8,8, + RGN_FRAC(1,2), + 4, + { RGN_FRAC(1,2)+0, RGN_FRAC(1,2)+4, 0, 4 }, + { 0, 1, 2, 3, 8, 9, 10, 11 }, + { 0*8, 2*8, 4*8, 6*8, 8*8, 10*8, 12*8, 14*8 }, + 16*8 +}; + + +static GFXDECODE_START( offtwall ) + GFXDECODE_ENTRY( "gfx1", 0, pfmolayout, 256, 32 ) /* sprites & playfield */ +GFXDECODE_END + + + +/************************************* + * + * Machine driver + * + *************************************/ + +static MACHINE_CONFIG_START( offtwall, offtwall_state ) + + /* basic machine hardware */ + MCFG_CPU_ADD("maincpu", M68000, ATARI_CLOCK_14MHz/2) + MCFG_CPU_PROGRAM_MAP(main_map) + + MCFG_MACHINE_START(offtwall) + MCFG_MACHINE_RESET(offtwall) + MCFG_NVRAM_ADD_1FILL("eeprom") + + /* video hardware */ + MCFG_VIDEO_ATTRIBUTES(VIDEO_UPDATE_BEFORE_VBLANK) + MCFG_GFXDECODE(offtwall) + MCFG_PALETTE_LENGTH(2048) + + MCFG_SCREEN_ADD("screen", RASTER) + MCFG_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16) + /* note: these parameters are from published specs, not derived */ + /* the board uses a VAD chip to generate video signals */ + MCFG_SCREEN_RAW_PARAMS(ATARI_CLOCK_14MHz/2, 456, 0, 336, 262, 0, 240) + MCFG_SCREEN_UPDATE(offtwall) + + MCFG_VIDEO_START(offtwall) + + /* sound hardware */ + MCFG_FRAGMENT_ADD(jsa_iii_mono_noadpcm) +MACHINE_CONFIG_END + + + +/************************************* + * + * ROM definition(s) + * + *************************************/ + +ROM_START( offtwall ) + ROM_REGION( 0x40000, "maincpu", 0 ) /* 4*64k for 68000 code */ + ROM_LOAD16_BYTE( "otw2012.bin", 0x00000, 0x20000, CRC(d08d81eb) SHA1(5a72aa2e4fc6455b94aa59a7719d0ddc8bcc80f2) ) + ROM_LOAD16_BYTE( "otw2013.bin", 0x00001, 0x20000, CRC(61c2553d) SHA1(343d39f9b75fd236e9769ec21ab65310f85e31ca) ) + + ROM_REGION( 0x14000, "jsa", 0 ) /* 64k for 6502 code */ + ROM_LOAD( "otw1020.bin", 0x10000, 0x4000, CRC(488112a5) SHA1(55e84855daacfa303d1031de8c9adb992a846e21) ) + ROM_CONTINUE( 0x04000, 0xc000 ) + + ROM_REGION( 0xc0000, "gfx1", ROMREGION_INVERT ) + ROM_LOAD( "otw1014.bin", 0x000000, 0x20000, CRC(4d64507e) SHA1(cb2ac41aecd2702cd57c746a6f5986cd753bc29e) ) + ROM_LOAD( "otw1016.bin", 0x020000, 0x20000, CRC(f5454f3a) SHA1(87d82bd227f7fcfd13b6f4ad88a573d1b96a4fc1) ) + ROM_LOAD( "otw1018.bin", 0x040000, 0x20000, CRC(17864231) SHA1(22f93fcb5d413281157ab8545647f3713f98c135) ) + ROM_LOAD( "otw1015.bin", 0x060000, 0x20000, CRC(271f7856) SHA1(928bc5e7dc589ceb5f55e536b5a05c3866116a24) ) + ROM_LOAD( "otw1017.bin", 0x080000, 0x20000, CRC(7f7f8012) SHA1(1123ea3c6cd2c73617a87d6a5bbb26fca8941af3) ) + ROM_LOAD( "otw1019.bin", 0x0a0000, 0x20000, CRC(9efe511b) SHA1(db1f1d8792bf497bc9ad652b0b7d78c3abf0e817) ) + + ROM_REGION( 0x1000, "eeprom", 0 ) + ROM_LOAD( "offtwall-eeprom.bin", 0x0000, 0x1000, CRC(73dc2139) SHA1(28ee9be4b5a65708a4f3e7d88e98af15cd9badca) ) +ROM_END + + +ROM_START( offtwallc ) + ROM_REGION( 0x40000, "maincpu", 0 ) /* 4*64k for 68000 code */ + ROM_LOAD16_BYTE( "090-2612.rom", 0x00000, 0x20000, CRC(fc891a3f) SHA1(027815a20fbc6c0c9242768581b97362b39941c2) ) + ROM_LOAD16_BYTE( "090-2613.rom", 0x00001, 0x20000, CRC(805d79d4) SHA1(943ec9f408ba875bdf1794ce7d24803043480401) ) + + ROM_REGION( 0x14000, "jsa", 0 ) /* 64k for 6502 code */ + ROM_LOAD( "otw1020.bin", 0x10000, 0x4000, CRC(488112a5) SHA1(55e84855daacfa303d1031de8c9adb992a846e21) ) + ROM_CONTINUE( 0x04000, 0xc000 ) + + ROM_REGION( 0xc0000, "gfx1", ROMREGION_INVERT ) + ROM_LOAD( "090-1614.rom", 0x000000, 0x20000, CRC(307ed447) SHA1(acee15e58cd8def8e52a7586aa14240e1f8be319) ) + ROM_LOAD( "090-1616.rom", 0x020000, 0x20000, CRC(a5bd3d9b) SHA1(756d96eac2398dc68679b7641acbf0e79204eebb) ) + ROM_LOAD( "090-1618.rom", 0x040000, 0x20000, CRC(c7d9df5d) SHA1(d5e5fbb7faf42d865862b9ac60f94d20820b00f3) ) + ROM_LOAD( "090-1615.rom", 0x060000, 0x20000, CRC(ac3642c7) SHA1(bb57e039c113c4ce5702983c8e01dbe286d7b58e) ) + ROM_LOAD( "090-1617.rom", 0x080000, 0x20000, CRC(15208a89) SHA1(124484ab54959a1e6d9022a4f3ee4288a79c768b) ) + ROM_LOAD( "090-1619.rom", 0x0a0000, 0x20000, CRC(8a5d79b3) SHA1(0a202d20e6c86989ce2223e10eadf9009dd6ca8e) ) + + ROM_REGION( 0x1000, "eeprom", 0 ) + ROM_LOAD( "offtwall-eeprom.bin", 0x0000, 0x1000, CRC(73dc2139) SHA1(28ee9be4b5a65708a4f3e7d88e98af15cd9badca) ) +ROM_END + + + +/************************************* + * + * Driver initialization + * + *************************************/ + +static DRIVER_INIT( offtwall ) +{ + offtwall_state *state = machine.driver_data<offtwall_state>(); + + atarijsa_init(machine, "260010", 0x0040); + + /* install son-of-slapstic workarounds */ + state->m_spritecache_count = machine.device("maincpu")->memory().space(AS_PROGRAM)->install_legacy_read_handler(0x3fde42, 0x3fde43, FUNC(spritecache_count_r)); + state->m_bankswitch_base = machine.device("maincpu")->memory().space(AS_PROGRAM)->install_legacy_read_handler(0x037ec2, 0x037f39, FUNC(bankswitch_r)); + state->m_unknown_verify_base = machine.device("maincpu")->memory().space(AS_PROGRAM)->install_legacy_read_handler(0x3fdf1e, 0x3fdf1f, FUNC(unknown_verify_r)); +} + + +static DRIVER_INIT( offtwalc ) +{ + offtwall_state *state = machine.driver_data<offtwall_state>(); + + atarijsa_init(machine, "260010", 0x0040); + + /* install son-of-slapstic workarounds */ + state->m_spritecache_count = machine.device("maincpu")->memory().space(AS_PROGRAM)->install_legacy_read_handler(0x3fde42, 0x3fde43, FUNC(spritecache_count_r)); + state->m_bankswitch_base = machine.device("maincpu")->memory().space(AS_PROGRAM)->install_legacy_read_handler(0x037eca, 0x037f43, FUNC(bankswitch_r)); + state->m_unknown_verify_base = machine.device("maincpu")->memory().space(AS_PROGRAM)->install_legacy_read_handler(0x3fdf24, 0x3fdf25, FUNC(unknown_verify_r)); +} + + + +/************************************* + * + * Game driver(s) + * + *************************************/ + +GAME( 1991, offtwall, 0, offtwall, offtwall, offtwall, ROT0, "Atari Games", "Off the Wall (2/3-player upright)", 0 ) +GAME( 1991, offtwallc,offtwall, offtwall, offtwall, offtwalc, ROT0, "Atari Games", "Off the Wall (2-player cocktail)", 0 ) |