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dotrikun: try another method for video timing

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This commit is contained in:
hap 2016-08-19 20:09:28 +02:00
parent c2d6daa908
commit bd83f8edd7
1 changed files with 28 additions and 13 deletions
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41
src/mame/drivers/dotrikun.cpp
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@ -39,12 +39,14 @@ public:
: driver_device(mconfig, type, tag),
m_maincpu(*this, "maincpu"),
m_screen(*this, "screen"),
m_vram(*this, "vram")
m_vram(*this, "vram"),
m_scanline_off_timer(*this, "scanline_off")
{ }
required_device<cpu_device> m_maincpu;
required_device<screen_device> m_screen;
required_shared_ptr<UINT8> m_vram;
required_device<timer_device> m_scanline_off_timer;
UINT8 m_vram_latch;
UINT8 m_color;
@ -52,12 +54,32 @@ public:
DECLARE_WRITE8_MEMBER(vram_w);
DECLARE_WRITE8_MEMBER(color_w);
UINT32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
INTERRUPT_GEN_MEMBER(interrupt);
TIMER_DEVICE_CALLBACK_MEMBER(scanline_on);
TIMER_DEVICE_CALLBACK_MEMBER(scanline_off);
virtual void machine_start() override;
virtual void machine_reset() override;
};
TIMER_DEVICE_CALLBACK_MEMBER(dotrikun_state::scanline_off)
{
m_maincpu->set_unscaled_clock(XTAL_4MHz);
}
TIMER_DEVICE_CALLBACK_MEMBER(dotrikun_state::scanline_on)
{
// on vram fetch(every 8 pixels during active display), z80 is stalled for 2 clocks
if (param >= 0 && param < 192)
{
m_maincpu->set_unscaled_clock(XTAL_4MHz * 0.75);
m_scanline_off_timer->adjust(m_screen->time_until_pos(param, 128), param);
}
// vblank interrupt
else if (param == 192)
generic_pulse_irq_line(m_maincpu, 0, 1);
}
/*************************************
*
@ -87,12 +109,9 @@ UINT32 dotrikun_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap
{
for (int x = cliprect.min_x; x <= cliprect.max_x; x++)
{
// vram fetch
if ((x & 7) == 0)
{
// on vram fetch(every 8 pixels during active display), z80 is stalled for 2 clocks
m_maincpu->adjust_icount(-2);
m_vram_latch = m_vram[x >> 3 | y >> 1 << 4];
}
bitmap.pix16(y, x) = (m_vram_latch >> (~x & 7) & 1) ? m_color & 7 : m_color >> 3;
}
@ -145,11 +164,6 @@ INPUT_PORTS_END
*
*************************************/
INTERRUPT_GEN_MEMBER(dotrikun_state::interrupt)
{
generic_pulse_irq_line(m_maincpu, 0, 1);
}
void dotrikun_state::machine_start()
{
save_item(NAME(m_vram_latch));
@ -168,8 +182,9 @@ static MACHINE_CONFIG_START( dotrikun, dotrikun_state )
MCFG_CPU_ADD("maincpu", Z80, XTAL_4MHz)
MCFG_CPU_PROGRAM_MAP(dotrikun_map)
MCFG_CPU_IO_MAP(io_map)
MCFG_CPU_VBLANK_INT_DRIVER("screen", dotrikun_state, interrupt)
MCFG_TIMER_DRIVER_ADD_SCANLINE("scanline_on", dotrikun_state, scanline_on, "screen", 0, 1)
MCFG_TIMER_DRIVER_ADD("scanline_off", dotrikun_state, scanline_off)
/* video hardware */
MCFG_SCREEN_ADD("screen", RASTER)
MCFG_SCREEN_RAW_PARAMS(XTAL_4MHz, 128+128, 0, 128, 192+64, 0, 192)