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// license:BSD-3-Clause
// copyright-holders:Aaron Giles, Bryan McPhail
/***************************************************************************
Midway MCR-68k system
***************************************************************************/
#include "emu.h"
#include "audio/midway.h"
#include "includes/mcr68.h"
#define VERBOSE 0
/*************************************
*
* Generic MCR/68k machine initialization
*
*************************************/
MACHINE_START_MEMBER(mcr68_state,mcr68)
{
}
MACHINE_RESET_MEMBER(mcr68_state,mcr68)
{
/* for the most part all MCR/68k games are the same */
m_v493_callback = timer_expired_delegate(FUNC(mcr68_state::mcr68_493_callback),this);
}
/*************************************
*
* Scanline callback
*
*************************************/
TIMER_DEVICE_CALLBACK_MEMBER( mcr68_state::scanline_cb )
{
// VSYNC
if (param == 0)
{
if (VERBOSE)
logerror("--- VBLANK ---\n");
m_ptm->set_c1(0);
m_ptm->set_c1(1);
/* also set a timer to generate the 493 signal at a specific time before the next VBLANK */
/* the timing of this is crucial for Blasted and Tri-Sports, which check the timing of */
/* VBLANK and 493 using counter 2 */
machine().scheduler().timer_set(attotime::from_hz(30) - m_timing_factor, m_v493_callback);
}
// HSYNC
m_ptm->set_c3(0);
m_ptm->set_c3(1);
}
/*************************************
*
* MCR/68k interrupt central
*
*************************************/
TIMER_CALLBACK_MEMBER(mcr68_state::mcr68_493_off_callback)
{
m_maincpu->set_input_line(1, CLEAR_LINE);
}
TIMER_CALLBACK_MEMBER(mcr68_state::mcr68_493_callback)
{
m_maincpu->set_input_line(1, ASSERT_LINE);
machine().scheduler().timer_set(m_screen->scan_period(), timer_expired_delegate(FUNC(mcr68_state::mcr68_493_off_callback),this));
if (VERBOSE)
logerror("--- (INT1) ---\n");
}
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