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(MESS) amstrad: Allowed vpos counter to count past the active display. This allows raster interrupts to be set on a non-visible scanline. [Barry Rodewald]

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This commit is contained in:
mahlemiut 2013-10-12 01:52:30 +00:00
parent ab8f3ae1f6
commit ae78d9ab7d
1 changed files with 9 additions and 7 deletions
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16
src/mess/machine/amstrad.c
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@ -953,8 +953,7 @@ WRITE_LINE_MEMBER(amstrad_state::amstrad_plus_hsync_changed)
}
// CPC+/GX4000 DMA channels
amstrad_plus_handle_dma(); // a DMA command is handled at the leading edge of HSYNC (every 64us)
if(m_asic.de_start != 0)
m_asic.vpos++;
m_asic.vpos++;
}
}
m_gate_array.hsync = state ? 1 : 0;
@ -972,7 +971,6 @@ WRITE_LINE_MEMBER(amstrad_state::amstrad_vsync_changed)
/* Start of new frame */
m_gate_array.y = -1;
m_asic.vpos = 1;
m_asic.de_start = 0;
}
@ -994,7 +992,6 @@ WRITE_LINE_MEMBER(amstrad_state::amstrad_plus_vsync_changed)
/* Start of new frame */
m_gate_array.y = -1;
m_asic.vpos = 1;
m_asic.de_start = 0;
}
@ -1014,9 +1011,12 @@ WRITE_LINE_MEMBER(amstrad_state::amstrad_de_changed)
/* DE became active, store the starting MA and RA signals */
mc6845_device *mc6845 = m_crtc;
if(m_asic.de_start == 0)
m_asic.vpos = 1;
m_gate_array.ma = mc6845->get_ma();
m_gate_array.ra = mc6845->get_ra();
logerror("y = %d; ma = %02x; ra = %02x, address = %04x\n", m_gate_array.y, m_gate_array.ma, m_gate_array.ra, ( ( m_gate_array.ma & 0x3000 ) << 2 ) | ( ( m_gate_array.ra & 0x07 ) << 11 ) | ( ( m_gate_array.ma & 0x3ff ) << 1 ) );
//logerror("y = %d; ma = %02x; ra = %02x, address = %04x\n", m_gate_array.y, m_gate_array.ma, m_gate_array.ra, ( ( m_gate_array.ma & 0x3000 ) << 2 ) | ( ( m_gate_array.ra & 0x07 ) << 11 ) | ( ( m_gate_array.ma & 0x3ff ) << 1 ) );
amstrad_gate_array_get_video_data();
m_asic.de_start = 1;
}
@ -1035,6 +1035,8 @@ WRITE_LINE_MEMBER(amstrad_state::amstrad_plus_de_changed)
m_gate_array.ma = m_crtc->get_ma();
m_gate_array.ra = m_crtc->get_ra();
m_asic.h_start = m_gate_array.line_ticks;
if(m_asic.de_start == 0)
m_asic.vpos = 1;
m_asic.de_start = 1;
/* Start of screen */
@ -1426,7 +1428,7 @@ WRITE8_MEMBER(amstrad_state::amstrad_plus_asic_6000_w)
}
if(offset == 0x0800) // Programmable raster interrupt
{
// logerror("ASIC: Wrote %02x to PRI\n",data);
// logerror("ASIC: Wrote %02x to PRI\n",data);
m_asic.pri = data;
}
if(offset >= 0x0801 && offset <= 0x0803) // Split screen registers
@ -2570,7 +2572,7 @@ READ8_MEMBER(amstrad_state::amstrad_ppi_portb_r)
data |= 0x02;
}
logerror("amstrad_ppi_portb_r\n");
//logerror("amstrad_ppi_portb_r\n");
/* Schedule a write to PC2 */
timer_set(attotime::zero, TIMER_PC2_LOW);