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yutnori: replaced hack with protection [iq_132, Robbbert]

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This commit is contained in:
Robbbert 2018-12-11 19:41:52 +11:00
parent 147208b0b0
commit b4108e2422
2 changed files with 29 additions and 7 deletions
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33
src/mame/drivers/snowbros.cpp
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@ -520,13 +520,37 @@ void snowbros_state::finalttr_map(address_map &map)
}
// Yutnori protection.
// The sequence MEN is sent to the protection device, followed by the code request (4 bytes in all).
// After each byte, a number of NOPs are executed to give the device time to catch up.
// After the 4th byte, the code reads the device to get its response.
READ16_MEMBER(snowbros_state::yutnori_prot_r)
{
switch(m_yutnori_prot_val) // the 4th byte
{
case 0x33: // C3B6
return 0xcc;
case 0x60: // 4878
return 0xf9;
case 0xb8: // D820
return 0x74;
}
logerror("%s: Unhandled protection sequence found: %02X\n", machine().describe_context(), m_yutnori_prot_val);
return 0;
}
WRITE16_MEMBER(snowbros_state::yutnori_prot_w)
{
m_yutnori_prot_val = data;
}
void snowbros_state::yutnori_map(address_map &map)
{
map(0x000000, 0x03ffff).rom();
// 0x100000 clr.w on startup
// 0x200000 could be the protection device, it makes several writes, then executes an entire subroutine of NOPs..
map(0x200000, 0x200001).rw(FUNC(snowbros_state::yutnori_prot_r),FUNC(snowbros_state::yutnori_prot_w)); // protection
map(0x300000, 0x300001).portr("DSW1");
map(0x300002, 0x300003).portr("DSW2");
@ -2890,12 +2914,7 @@ void snowbros_state::init_hyperpac()
void snowbros_state::init_yutnori()
{
// presumably related to the PIC protection
uint16_t *rom = (uint16_t *)memregion("maincpu")->base();
rom[0x4878 / 2] = 0x4e71;
rom[0xd820 / 2] = 0x4e71;
rom[0xc3b6 / 2] = 0x4e71;
m_yutnori_prot_val = 0;
m_pandora->set_bg_pen(0xf0);
}

3
src/mame/includes/snowbros.h
View File

@ -67,6 +67,7 @@ private:
int m_sb3_music_is_playing;
int m_sb3_music;
uint8_t m_semicom_prot_offset;
uint16_t m_yutnori_prot_val;
DECLARE_WRITE8_MEMBER(snowbros_flipscreen_w);
DECLARE_WRITE8_MEMBER(bootleg_flipscreen_w);
@ -83,6 +84,8 @@ private:
DECLARE_WRITE8_MEMBER(twinadv_oki_bank_w);
DECLARE_WRITE16_MEMBER(sb3_sound_w);
DECLARE_READ16_MEMBER(toto_read);
DECLARE_WRITE16_MEMBER(yutnori_prot_w);
DECLARE_READ16_MEMBER(yutnori_prot_r);
DECLARE_MACHINE_RESET(semiprot);
DECLARE_MACHINE_RESET(finalttr);