OK, here are the modifications:
1) Create a new input:
Code:
static INPUT_PORTS_START (boblbobl2)
PORT_INCLUDE (sboblbob)
PORT_MODIFY ("IN0")
PORT_BIT (0x04, IP_ACTIVE_LOW, IPT_COIN2) PORT_IMPULSE (1)
PORT_BIT (0x08, IP_ACTIVE_LOW, IPT_COIN1) PORT_IMPULSE (1)
PORT_BIT (0x80, IP_ACTIVE_HIGH, IPT_UNKNOWN) // Must be low or the game freezes!
INPUT_PORTS_END
2) Fix the gfx1 loading order:
Code:
ROM_REGION (0x80000, "gfx1", ROMREGION_INVERT)
ROM_LOAD ("gfx11.bin", 0x00000, 0x10000, CRC (76f2b367) SHA1 (3e357a5642c8747df77a995057cecdf96f3130ab))
ROM_LOAD ("gfx10.bin", 0x10000, 0x10000, CRC (d370f499) SHA1 (94ce157ff1a53fabf08abe5467531b94a56666a5))
ROM_LOAD ("a78-13.16", 0x20000, 0x08000, CRC (d0af35c5) SHA1 (c5a89f4d73acc0db86654540b3abfd77b3757db5)) // Match
ROM_LOAD ("a78-14.17", 0x28000, 0x08000, CRC (7b5369a8) SHA1 (1307b26d80e6f36ebe6c442bebec41d20066eaf9)) // Match
// 0x30000 - 0x3FFFF empty
ROM_LOAD ("gfx8.bin", 0x40000, 0x10000, CRC (677840e8) SHA1 (995b2125ca18910d7d4b96078f4ecb17465c4151))
ROM_LOAD ("gfx7.bin", 0x50000, 0x10000, CRC (702f61c0) SHA1 (2f294ab2b0286736a64ea2bfc95d855aa5b41ada))
ROM_LOAD ("a78-19.34", 0x60000, 0x08000, CRC (66e9438c) SHA1 (b94e62b6fbe7f4e08086d0365afc5cff6e0ccafd)) // Match
ROM_LOAD ("a78-20.35", 0x68000, 0x08000, CRC (9ef863ad) SHA1 (29f91b5a3765e4d6e6c3382db1d8d8297b6e56c8)) // Match
// 0x70000 - 0x7FFFF empty
3) Update the game row:
Code:
GAME (1988, boblbobl2, bublbobl, boblbobl, boblbobl2, bublbobl_state, bublbobl, ROT0, "Datsu bootleg", "Super Bobble Bobble (Datsu bootleg)", GAME_SUPPORTS_SAVE)
As Dullaron said, should be better to rename the name boblbobl2.