MAMEWorld Forums - EmuChat - Re: Actually is fixed here on my PC....

Code:

TIMER_DEVICE_CALLBACK_MEMBER(megasys1_state::megasys1A_scanline_kazan)
{
	int scanline = param;

	if(scanline == 240)		// vblank clear all lines
	{
		m_maincpu->set_input_line(3, CLEAR_LINE);
		m_maincpu->set_input_line(2, CLEAR_LINE);
		m_maincpu->set_input_line(1, CLEAR_LINE);
	}
	
	if(scanline == 0)
		m_maincpu->set_input_line(1, ASSERT_LINE);

	if(scanline == 128)
		m_maincpu->set_input_line(2, ASSERT_LINE);

	if(scanline == 192)		// completely a guess 
		m_maincpu->set_input_line(3, ASSERT_LINE);
}

and with this line commented out in original source enabled again:

Code:

m_rom_maincpu[0x00006e/2] = 0x0420; // the only game that does not like lev 3 interrupts

NOTE 1: this code breaks ALL other games in the driver, so it should be implemented only for Kazan.
NOTE 2: it's a bit hacky, expecially the m_rom_maincpu patch. Though, it's necessary otherwise the game crash after the boot. This patch was enabled before the bug appeared and then commented out.

EDIT for Developers: the usage of HOLD_LINE with scanlines timers should be deprecated in favour of ASSERT_LINE and CLEAR_LINE. Probably my implementation is not 100% correct but hey, it took me an hour of investigations "fix" a 7 years old bug.

Edited by Mamesick (06/19/15 09:27 PM)