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author Nigel Barnes <Pernod70@users.noreply.github.com>2018-04-16 13:16:05 +0100
committer Nigel Barnes <Pernod70@users.noreply.github.com>2018-04-16 13:17:44 +0100
commited3345e84f024fdfe4e52a9a13469f8747fa45ce (patch)
treed96994a44e10bf62fac83b30888a2c38dca61081
parent001ec452c96e50a2749bbedd706cfc411e157220 (diff)
electron: Improved video handling.
- Fixed wrap-around for non-standard screen start addresses - Added RAM contention during screen update - Improved interrupt times
-rw-r--r--src/mame/drivers/electron.cpp1
-rw-r--r--src/mame/includes/electron.h5
-rw-r--r--src/mame/machine/electron.cpp18
-rw-r--r--src/mame/video/electron.cpp43
4 files changed, 37 insertions, 30 deletions
diff --git a/src/mame/drivers/electron.cpp b/src/mame/drivers/electron.cpp
index 09d7ec744d6..dd7dc8ed1f8 100644
--- a/src/mame/drivers/electron.cpp
+++ b/src/mame/drivers/electron.cpp
@@ -218,6 +218,7 @@ MACHINE_CONFIG_START(electron_state::electron)
MCFG_SCREEN_ADD("screen", RASTER)
MCFG_SCREEN_RAW_PARAMS(16_MHz_XTAL, 1024, 0, 640, 312, 0, 256)
+ //MCFG_SCREEN_RAW_PARAMS(16_MHz_XTAL, 1024, 264, 264 + 640, 312, 31, 31 + 256)
MCFG_SCREEN_UPDATE_DRIVER(electron_state, screen_update_electron)
MCFG_SCREEN_VIDEO_ATTRIBUTES(VIDEO_UPDATE_SCANLINE)
MCFG_SCREEN_PALETTE("palette")
diff --git a/src/mame/includes/electron.h b/src/mame/includes/electron.h
index 03066fb852a..ba11ea1d2f6 100644
--- a/src/mame/includes/electron.h
+++ b/src/mame/includes/electron.h
@@ -119,15 +119,14 @@ private:
uint8_t rompage;
uint16_t screen_start;
uint16_t screen_base;
- int screen_size;
+ uint16_t screen_size;
uint16_t screen_addr;
- uint8_t *vram;
+ int screen_dispend;
int current_pal[16];
int communication_mode;
int screen_mode;
int cassette_motor_mode;
int capslock_mode;
- // int scanline;
/* tape reading related */
uint32_t tape_value;
int tape_steps;
diff --git a/src/mame/machine/electron.cpp b/src/mame/machine/electron.cpp
index 6e1236fdba0..fa7a085c697 100644
--- a/src/mame/machine/electron.cpp
+++ b/src/mame/machine/electron.cpp
@@ -18,9 +18,9 @@ void electron_state::waitforramsync()
{
int cycles = 0;
- if (!(m_ula.screen_mode & 4) && m_screen->hpos()<640)
+ if (!(m_ula.screen_mode & 4) && (m_screen->vpos() > m_screen->visible_area().min_y) && (m_screen->vpos() < m_screen->visible_area().max_y) && !m_screen->hblank())
{
- cycles += (640 - m_screen->hpos()) / 8;
+ cycles += (m_screen->visible_area().max_x - m_screen->hpos()) / 16;
}
if (cycles & 1) cycles++;
@@ -156,7 +156,7 @@ READ8_MEMBER(electron_state::electron_mem_r)
case 0x00: /* Normal */
/* The processor will run at 1MHz during an access cycle to the RAM */
m_maincpu->set_clock_scale(0.5f);
- //waitforramsync();
+ waitforramsync();
break;
case 0x01: /* Turbo */
@@ -177,7 +177,7 @@ WRITE8_MEMBER(electron_state::electron_mem_w)
case 0x00: /* Normal */
/* The processor will run at 1MHz during an access cycle to the RAM */
m_maincpu->set_clock_scale(0.5f);
- //waitforramsync();
+ waitforramsync();
break;
case 0x01: /* Turbo */
@@ -335,7 +335,8 @@ READ8_MEMBER(electron_state::electron_sheila_r)
}
static const int electron_palette_offset[4] = { 0, 4, 5, 1 };
-static const uint16_t electron_screen_base[8] = { 0x3000, 0x3000, 0x3000, 0x4000, 0x5800, 0x5800, 0x6000, 0x5800 };
+static const uint16_t electron_screen_base[8] = { 0x3000, 0x3000, 0x3000, 0x4000, 0x5800, 0x5800, 0x6000, 0x6000 };
+static const int electron_mode_end[8] = { 255, 255, 255 ,249 ,255, 255, 249, 249 };
WRITE8_MEMBER(electron_state::electron_sheila_w)
{
@@ -358,7 +359,7 @@ WRITE8_MEMBER(electron_state::electron_sheila_w)
logerror( "screen_start changed to %04x\n", m_ula.screen_start );
break;
case 0x03: /* Screen start address #2 */
- m_ula.screen_start = ( m_ula.screen_start & 0x1c0 ) | ( ( data & 0x3f ) << 9 );
+ m_ula.screen_start = ( m_ula.screen_start & 0x1ff ) | ( ( data & 0x3f ) << 9 );
logerror( "screen_start changed to %04x\n", m_ula.screen_start );
break;
case 0x04: /* Cassette data shift register */
@@ -429,7 +430,7 @@ WRITE8_MEMBER(electron_state::electron_sheila_w)
m_ula.screen_mode = ( data >> 3 ) & 0x07;
m_ula.screen_base = electron_screen_base[ m_ula.screen_mode ];
m_ula.screen_size = 0x8000 - m_ula.screen_base;
- m_ula.vram = (uint8_t *)m_ram->pointer() + m_ula.screen_base;
+ m_ula.screen_dispend = electron_mode_end[ m_ula.screen_mode ];
logerror( "ULA: screen mode set to %d\n", m_ula.screen_mode );
m_ula.cassette_motor_mode = ( data >> 6 ) & 0x01;
m_cassette->change_state(m_ula.cassette_motor_mode ? CASSETTE_MOTOR_ENABLED : CASSETTE_MOTOR_DISABLED, CASSETTE_MOTOR_DISABLED );
@@ -494,9 +495,8 @@ void electron_state::machine_reset()
m_ula.screen_start = 0x3000;
m_ula.screen_base = 0x3000;
m_ula.screen_size = 0x8000 - 0x3000;
- m_ula.screen_addr = 0;
+ m_ula.screen_addr = 0x3000;
m_ula.tape_running = 0;
- m_ula.vram = (uint8_t *)m_ram->pointer() + m_ula.screen_base;
m_mrb_mapped = true;
m_vdu_drivers = false;
diff --git a/src/mame/video/electron.cpp b/src/mame/video/electron.cpp
index 9734ded6ced..64f6b1b11ec 100644
--- a/src/mame/video/electron.cpp
+++ b/src/mame/video/electron.cpp
@@ -72,9 +72,10 @@ void electron_state::video_start()
m_scanline_timer->adjust( m_screen->time_until_pos(0), 0, m_screen->scan_period() );
}
-inline uint8_t electron_state::read_vram( uint16_t addr )
+inline uint8_t electron_state::read_vram( uint16_t addr )
{
- return m_ula.vram[ addr % m_ula.screen_size ];
+ if ( addr & 0x8000 ) addr -= m_ula.screen_size;
+ return m_ram->read( addr );
}
inline void electron_state::electron_plot_pixel(bitmap_ind16 &bitmap, int x, int y, uint32_t color)
@@ -84,7 +85,9 @@ inline void electron_state::electron_plot_pixel(bitmap_ind16 &bitmap, int x, int
uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
- int x = 0;
+ int min_x = screen.visible_area().min_x;
+ int min_y = screen.visible_area().min_y;
+ int x = min_x;
int pal[16];
int scanline = screen.vpos();
rectangle r = cliprect;
@@ -114,7 +117,7 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
case 0:
for( int i = 0; i < 80; i++ )
{
- uint8_t pattern = read_vram( m_ula.screen_addr + (i << 3) );
+ uint8_t pattern = read_vram( m_ula.screen_addr + i * 8 );
electron_plot_pixel( bitmap, x++, scanline, pal[(pattern>>7)& 1] );
electron_plot_pixel( bitmap, x++, scanline, pal[(pattern>>6)& 1] );
electron_plot_pixel( bitmap, x++, scanline, pal[(pattern>>5)& 1] );
@@ -125,7 +128,7 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
electron_plot_pixel( bitmap, x++, scanline, pal[(pattern>>0)& 1] );
}
m_ula.screen_addr++;
- if ( ( scanline & 0x07 ) == 7 )
+ if ( ( ( scanline - min_y ) & 0x07 ) == 7 )
m_ula.screen_addr += 0x278;
break;
@@ -143,7 +146,7 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
electron_plot_pixel( bitmap, x++, scanline, pal[m_map4[pattern>>0]] );
}
m_ula.screen_addr++;
- if ( ( scanline & 0x07 ) == 7 )
+ if ( ( ( scanline - min_y ) & 0x07 ) == 7 )
m_ula.screen_addr += 0x278;
break;
@@ -161,12 +164,12 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
electron_plot_pixel( bitmap, x++, scanline, pal[m_map16[pattern>>0]] );
}
m_ula.screen_addr++;
- if ( ( scanline & 0x07 ) == 7 )
+ if ( ( ( scanline - min_y ) & 0x07 ) == 7 )
m_ula.screen_addr += 0x278;
break;
case 3:
- if ( ( scanline > 249 ) || ( scanline % 10 >= 8 ) )
+ if ( ( ( scanline - min_y ) > 249 ) || ( ( scanline - min_y ) % 10 >= 8 ) )
bitmap.fill(7, r );
else
{
@@ -184,7 +187,7 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
}
m_ula.screen_addr++;
}
- if ( scanline % 10 == 9 )
+ if ( ( scanline - min_y ) % 10 == 9 )
m_ula.screen_addr += 0x278;
break;
@@ -211,7 +214,7 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
electron_plot_pixel( bitmap, x++, scanline, pal[(pattern>>0)&1] );
}
m_ula.screen_addr++;
- if ( ( scanline & 0x07 ) == 7 )
+ if ( ( ( scanline - min_y ) & 0x07 ) == 7 )
m_ula.screen_addr += 0x138;
break;
@@ -237,12 +240,12 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
electron_plot_pixel( bitmap, x++, scanline, pal[m_map4[pattern>>0]] );
}
m_ula.screen_addr++;
- if ( ( scanline & 0x07 ) == 7 )
+ if ( ( ( scanline - min_y ) & 0x07 ) == 7 )
m_ula.screen_addr += 0x138;
break;
case 6:
- if ( ( scanline > 249 ) || ( scanline % 10 >= 8 ) )
+ if ( ( ( scanline - min_y ) > 249) || ( ( scanline - min_y ) % 10 >= 8 ) )
bitmap.fill(7, r );
else
{
@@ -267,11 +270,13 @@ uint32_t electron_state::screen_update_electron(screen_device &screen, bitmap_in
electron_plot_pixel( bitmap, x++, scanline, pal[(pattern>>0)&1] );
}
m_ula.screen_addr++;
- if ( ( scanline % 10 ) == 7 )
+ if ( ( ( scanline - min_y ) % 10 ) == 7 )
m_ula.screen_addr += 0x138;
}
break;
}
+ if ( m_ula.screen_addr & 0x8000 )
+ m_ula.screen_addr -= m_ula.screen_size;
return 0;
}
@@ -280,14 +285,16 @@ TIMER_CALLBACK_MEMBER(electron_state::electron_scanline_interrupt)
{
switch (m_screen->vpos())
{
- case 43:
+ case 99:
electron_interrupt_handler( INT_SET, INT_RTC );
break;
- case 199:
- electron_interrupt_handler( INT_SET, INT_DISPLAY_END );
+ case 249:
+ case 255:
+ if ( m_screen->vpos() == m_ula.screen_dispend )
+ electron_interrupt_handler( INT_SET, INT_DISPLAY_END );
break;
- case 256:
- m_ula.screen_addr = m_ula.screen_start - m_ula.screen_base;
+ case 311:
+ m_ula.screen_addr = m_ula.screen_start;
break;
}
}