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-rw-r--r--src/mame/machine/gamecom.c629
1 files changed, 629 insertions, 0 deletions
diff --git a/src/mame/machine/gamecom.c b/src/mame/machine/gamecom.c
new file mode 100644
index 00000000000..148a0585928
--- /dev/null
+++ b/src/mame/machine/gamecom.c
@@ -0,0 +1,629 @@
+// license:BSD-3-Clause
+// copyright-holders:Wilbert Pol, Robbbert
+
+#include "includes/gamecom.h"
+
+
+
+static const int gamecom_timer_limit[8] = { 2, 1024, 2048, 4096, 8192, 16384, 32768, 65536 };
+
+TIMER_CALLBACK_MEMBER(gamecom_state::gamecom_clock_timer_callback)
+{
+ UINT8 val = m_p_ram[SM8521_CLKT] + 1;
+ m_p_ram[SM8521_CLKT] = ( m_p_ram[SM8521_CLKT] & 0xC0 ) | (val & 0x3f);
+ m_maincpu->set_input_line(sm8500_cpu_device::CK_INT, ASSERT_LINE );
+}
+
+void gamecom_state::machine_reset()
+{
+ UINT8 *rom = m_region_kernel->base();
+ m_bank1->set_base(rom);
+ m_bank2->set_base(rom);
+ m_bank3->set_base(rom);
+ m_bank4->set_base(rom);
+
+ m_cart_ptr = NULL;
+ m_lch_reg = 0x07;
+ m_lcv_reg = 0x27;
+ m_lcdc_reg = 0xb0;
+
+ std::string region_tag;
+ m_cart1_rom = memregion(region_tag.assign(m_cart1->tag()).append(GENERIC_ROM_REGION_TAG).c_str());
+ m_cart2_rom = memregion(region_tag.assign(m_cart2->tag()).append(GENERIC_ROM_REGION_TAG).c_str());
+}
+
+void gamecom_state::gamecom_set_mmu(UINT8 mmu, UINT8 data)
+{
+ if (data < 0x20)
+ {
+ /* select internal ROM bank */
+ switch (mmu)
+ {
+ case 1: m_bank1->set_base(m_region_kernel->base() + (data << 13)); break;
+ case 2: m_bank2->set_base(m_region_kernel->base() + (data << 13)); break;
+ case 3: m_bank3->set_base(m_region_kernel->base() + (data << 13)); break;
+ case 4: m_bank4->set_base(m_region_kernel->base() + (data << 13)); break;
+ }
+ }
+ else
+ {
+ /* select cartridge bank */
+ if (m_cart_ptr)
+ {
+ switch (mmu)
+ {
+ case 1: m_bank1->set_base(m_cart_ptr + (data << 13)); break;
+ case 2: m_bank2->set_base(m_cart_ptr + (data << 13)); break;
+ case 3: m_bank3->set_base(m_cart_ptr + (data << 13)); break;
+ case 4: m_bank4->set_base(m_cart_ptr + (data << 13)); break;
+ }
+ }
+ }
+}
+
+void gamecom_state::handle_stylus_press( int column )
+{
+ UINT16 data = m_io_grid[column]->read();
+ if (data)
+ {
+ UINT16 stylus_y = data ^ 0x3ff;
+ m_p_ram[SM8521_P0] = stylus_y;
+ m_p_ram[SM8521_P1] = ( m_p_ram[SM8521_P1] & 0xFC ) | ( stylus_y >> 8 );
+ }
+ else
+ {
+ m_p_ram[SM8521_P0] = 0xFF;
+ m_p_ram[SM8521_P1] |= 3;
+ }
+}
+
+void gamecom_state::handle_input_press(UINT16 mux_data)
+{
+ switch( mux_data )
+ {
+ case 0xFFFB:
+ /* column #0 */
+ /* P0 bit 0 cleared => 01 */
+ /* P0 bit 1 cleared => 0E */
+ /* P0 bit 2 cleared => 1B */
+ /* P0 bit 3 cleared => etc */
+ /* P0 bit 4 cleared => */
+ /* P0 bit 5 cleared => */
+ /* P0 bit 6 cleared => */
+ /* P0 bit 7 cleared => */
+ /* P1 bit 0 cleared => */
+ /* P1 bit 1 cleared => */
+ handle_stylus_press(0);
+ break;
+ case 0xFFF7: /* column #1 */
+ handle_stylus_press(1);
+ break;
+ case 0xFFEF: /* column #2 */
+ handle_stylus_press(2);
+ break;
+ case 0xFFDF: /* column #3 */
+ handle_stylus_press(3);
+ break;
+ case 0xFFBF: /* column #4 */
+ handle_stylus_press(4);
+ break;
+ case 0xFF7F: /* column #5 */
+ handle_stylus_press(5);
+ break;
+ case 0xFEFF: /* column #6 */
+ handle_stylus_press(6);
+ break;
+ case 0xFDFF: /* column #7 */
+ handle_stylus_press(7);
+ break;
+ case 0xFBFF: /* column #8 */
+ handle_stylus_press(8);
+ break;
+ case 0xF7FF: /* column #9 */
+ handle_stylus_press(9);
+ break;
+ case 0xEFFF: /* column #10 */
+ handle_stylus_press(10);
+ break;
+ case 0xDFFF: /* column #11 */
+ handle_stylus_press(11);
+ break;
+ case 0xBFFF: /* column #12 */
+ handle_stylus_press(12);
+ break;
+ case 0x7FFF: /* keys #1 */
+ /* P0 bit 0 cleared => 83 (up) */
+ /* P0 bit 1 cleared => 84 (down) */
+ /* P0 bit 2 cleared => 85 (left) */
+ /* P0 bit 3 cleared => 86 (right) */
+ /* P0 bit 4 cleared => 87 (menu) */
+ /* P0 bit 5 cleared => 8A (pause) */
+ /* P0 bit 6 cleared => 89 (sound) */
+ /* P0 bit 7 cleared => 8B (button A) */
+ /* P1 bit 0 cleared => 8C (button B) */
+ /* P1 bit 1 cleared => 8D (button C) */
+ m_p_ram[SM8521_P0] = m_io_in0->read();
+ m_p_ram[SM8521_P1] = (m_p_ram[SM8521_P1] & 0xFC) | ( m_io_in1->read() & 3 );
+ break;
+ case 0xFFFF: /* keys #2 */
+ /* P0 bit 0 cleared => 88 (power) */
+ /* P0 bit 1 cleared => 8E (button D) */
+ /* P0 bit 2 cleared => A0 */
+ /* P0 bit 3 cleared => A0 */
+ /* P0 bit 4 cleared => A0 */
+ /* P0 bit 5 cleared => A0 */
+ /* P0 bit 6 cleared => A0 */
+ /* P0 bit 7 cleared => A0 */
+ /* P1 bit 0 cleared => A0 */
+ /* P1 bit 1 cleared => A0 */
+ m_p_ram[SM8521_P0] = (m_p_ram[SM8521_P0] & 0xFC) | ( m_io_in2->read() & 3 );
+ m_p_ram[SM8521_P1] = 0xFF;
+ break;
+ }
+}
+
+WRITE8_MEMBER( gamecom_state::gamecom_pio_w )
+{
+ offset += 0x14;
+ m_p_ram[offset] = data;
+ switch (offset)
+ {
+ case SM8521_P1:
+ case SM8521_P2:
+ handle_input_press(m_p_ram[SM8521_P1] | (m_p_ram[SM8521_P2] << 8));
+ break;
+ case SM8521_P3:
+ /* P3 bit7 clear, bit6 set -> enable cartridge port #0? */
+ /* P3 bit6 clear, bit7 set -> enable cartridge port #1? */
+ switch (data & 0xc0)
+ {
+ case 0x40: m_cart_ptr = m_cart1_rom->base(); break;
+ case 0x80: m_cart_ptr = m_cart2_rom->base(); break;
+ default: m_cart_ptr = NULL; break;
+ }
+ return;
+ }
+}
+
+READ8_MEMBER( gamecom_state::gamecom_pio_r )
+{
+ return m_p_ram[offset + 0x14];
+}
+
+READ8_MEMBER( gamecom_state::gamecom_internal_r )
+{
+// ToDo: Read from vblank bit
+// if(SM8521_LCV == offset + 0x20)
+// popmessage("Read from vblank bit, TODO");
+
+ return m_p_ram[offset + 0x20];
+}
+
+/* TODO: preliminary, proper formula not yet understood (and manual doesn't help much either) */
+void gamecom_state::recompute_lcd_params()
+{
+ int vblank_period,hblank_period;
+ int H_timing,V_timing;
+ int pixel_clock;
+ attoseconds_t refresh;
+
+ if(m_lch_reg != 7)
+ popmessage("LCH = %02x!",m_lch_reg);
+
+ if((m_lcdc_reg & 0xf) != 0)
+ popmessage("LCDC = %02x!",m_lcdc_reg);
+
+ if(m_lcv_reg != 0x27)
+ popmessage("LCV = %02x!",m_lcv_reg);
+
+ H_timing = ((m_lch_reg & 0x1f) + 1) * 200/4;
+ V_timing = (m_lcv_reg & 0x1f);
+ pixel_clock = (XTAL_11_0592MHz / 2); // TODO: divisor actually settable
+
+ rectangle visarea(0, 200-1, 0, 160-1); // TODO: check settings
+
+ vblank_period = (V_timing + 160);
+ hblank_period = (H_timing + 200);
+
+ refresh = HZ_TO_ATTOSECONDS(pixel_clock) * (hblank_period) * vblank_period;
+ machine().first_screen()->configure((hblank_period), (vblank_period), visarea, refresh );
+}
+
+WRITE8_MEMBER( gamecom_state::gamecom_internal_w )
+{
+ offset += 0x20;
+ switch( offset )
+ {
+ case SM8521_MMU0: /* disable bootstrap ROM? most likely not written to on game.com */
+ logerror( "Write to MMU0\n" );
+ break;
+ case SM8521_MMU1:
+ gamecom_set_mmu(1, data);
+ break;
+ case SM8521_MMU2:
+ gamecom_set_mmu(2, data);
+ break;
+ case SM8521_MMU3:
+ gamecom_set_mmu(3, data);
+ break;
+ case SM8521_MMU4:
+ gamecom_set_mmu(4, data);
+ break;
+
+ /* Video hardware and DMA */
+ case SM8521_DMBR:
+ data &= 0x7f;
+ break;
+ case SM8521_TM0D:
+ m_timer[0].check_value = data;
+ return;
+ case SM8521_TM0C:
+ m_timer[0].enabled = data & 0x80;
+ m_timer[0].state_limit = gamecom_timer_limit[data & 0x07] >> 1;
+ m_timer[0].state_count = 0;
+ m_p_ram[SM8521_TM0D] = 0;
+ break;
+ case SM8521_TM1D:
+ m_timer[1].check_value = data;
+ return;
+ case SM8521_TM1C:
+ m_timer[1].enabled = data & 0x80;
+ m_timer[1].state_limit = gamecom_timer_limit[data & 0x07] >> 1;
+ m_timer[1].state_count = 0;
+ m_p_ram[SM8521_TM1D] = 0;
+ break;
+ case SM8521_CLKT: /* bit 6-7 */
+ if ( data & 0x80 )
+ {
+ /* timer run */
+ if ( data & 0x40 )
+ {
+ /* timer resolution 1 minute */
+ m_clock_timer->adjust(attotime::from_seconds(1), 0, attotime::from_seconds(60));
+ }
+ else
+ {
+ /* TImer resolution 1 second */
+ m_clock_timer->adjust(attotime::from_seconds(1), 0, attotime::from_seconds(1));
+ }
+ }
+ else
+ {
+ /* disable timer reset */
+ m_clock_timer->enable( 0 );
+ data &= 0xC0;
+ }
+ break;
+
+ case SM8521_LCDC:
+ m_lcdc_reg = data;
+ recompute_lcd_params();
+ break;
+
+ case SM8521_LCH:
+ /*
+ --x- ---- Horizontal DOT size (160 / 200)
+ ---x xxxx H-Timing bits
+ */
+ m_lch_reg = data;
+ recompute_lcd_params();
+ break;
+
+ case SM8521_LCV:
+ /*
+ x--- ---- V-blank bit (R)
+ -xx- ---- V-line size bits (100 / 160 / 200 / undef)
+ ---x xxxx V-Blank width bits
+ */
+ m_lcv_reg = data;
+ recompute_lcd_params();
+ break;
+
+ /* Sound */
+ case SM8521_SGC:
+ /*
+ x--- ---- enable sound output
+ ---- x--- enable DAC
+ ---- -x-- enable SG2
+ ---- --x- enable SG1
+ ---- ---x enable SG0
+ */
+ m_sound.sgc = data;
+ break;
+ case SM8521_SG0L:
+ m_sound.sg0l = data;
+ break;
+ case SM8521_SG1L:
+ m_sound.sg1l = data;
+ break;
+ case SM8521_SG0TH:
+ m_sound.sg0t = ( m_sound.sg0t & 0xFF ) | ( data << 8 );
+ break;
+ case SM8521_SG0TL:
+ m_sound.sg0t = ( m_sound.sg0t & 0xFF00 ) | data;
+ break;
+ case SM8521_SG1TH:
+ m_sound.sg1t = ( m_sound.sg1t & 0xFF ) | ( data << 8 );
+ break;
+ case SM8521_SG1TL:
+ m_sound.sg1t = ( m_sound.sg1t & 0xFF00 ) | data;
+ break;
+ case SM8521_SG2L:
+ m_sound.sg2l = data;
+ break;
+ case SM8521_SG2TH:
+ m_sound.sg2t = ( m_sound.sg2t & 0xFF ) | ( data << 8 );
+ break;
+ case SM8521_SG2TL:
+ m_sound.sg2t = ( m_sound.sg2t & 0xFF00 ) | data;
+ break;
+ case SM8521_SGDA:
+ m_sound.sgda = data;
+ if((m_sound.sgc & 0x88) == 0x88)
+ m_dac->write_unsigned8(data);
+ break;
+
+ case SM8521_SG0W0:
+ case SM8521_SG0W1:
+ case SM8521_SG0W2:
+ case SM8521_SG0W3:
+ case SM8521_SG0W4:
+ case SM8521_SG0W5:
+ case SM8521_SG0W6:
+ case SM8521_SG0W7:
+ case SM8521_SG0W8:
+ case SM8521_SG0W9:
+ case SM8521_SG0W10:
+ case SM8521_SG0W11:
+ case SM8521_SG0W12:
+ case SM8521_SG0W13:
+ case SM8521_SG0W14:
+ case SM8521_SG0W15:
+ m_sound.sg0w[offset - SM8521_SG0W0] = data;
+ break;
+ case SM8521_SG1W0:
+ case SM8521_SG1W1:
+ case SM8521_SG1W2:
+ case SM8521_SG1W3:
+ case SM8521_SG1W4:
+ case SM8521_SG1W5:
+ case SM8521_SG1W6:
+ case SM8521_SG1W7:
+ case SM8521_SG1W8:
+ case SM8521_SG1W9:
+ case SM8521_SG1W10:
+ case SM8521_SG1W11:
+ case SM8521_SG1W12:
+ case SM8521_SG1W13:
+ case SM8521_SG1W14:
+ case SM8521_SG1W15:
+ m_sound.sg1w[offset - SM8521_SG1W0] = data;
+ break;
+
+ /* Reserved addresses */
+ case SM8521_18: case SM8521_1B:
+ case SM8521_29: case SM8521_2A: case SM8521_2F:
+ case SM8521_33: case SM8521_3E: case SM8521_3F:
+ case SM8521_41: case SM8521_43: case SM8521_45: case SM8521_4B:
+ case SM8521_4F:
+ case SM8521_55: case SM8521_56: case SM8521_57: case SM8521_58:
+ case SM8521_59: case SM8521_5A: case SM8521_5B: case SM8521_5C:
+ case SM8521_5D:
+ logerror( "%X: Write to reserved address (0x%02X). Value written: 0x%02X\n", m_maincpu->pc(), offset, data );
+ break;
+ }
+ m_p_ram[offset] = data;
+}
+
+
+/* The manual is not conclusive as to which bit of the DMVP register (offset 0x3D) determines
+ which page for source or destination is used */
+WRITE8_MEMBER( gamecom_state::gamecom_handle_dma )
+{
+ UINT8 dmc = m_p_ram[SM8521_DMC];
+ m_dma.overwrite_mode = dmc & 0x01;
+ m_dma.transfer_mode = dmc & 0x06;
+ m_dma.decrement_x = dmc & 0x08;
+ m_dma.decrement_y = dmc & 0x10;
+ m_dma.enabled = dmc & 0x80;
+ if ( !m_dma.enabled )
+ {
+ return;
+ }
+
+ m_dma.width_x = m_p_ram[SM8521_DMDX];
+ m_dma.width_x_count = 0;
+ m_dma.width_y = m_p_ram[SM8521_DMDY];
+ m_dma.width_y_count = 0;
+ m_dma.source_x = m_p_ram[SM8521_DMX1];
+ m_dma.source_x_current = m_dma.source_x;
+ m_dma.source_y = m_p_ram[SM8521_DMY1];
+ m_dma.source_width = ( m_p_ram[SM8521_LCH] & 0x20 ) ? 50 : 40;
+ m_dma.dest_x = m_p_ram[SM8521_DMX2];
+ m_dma.dest_x_current = m_dma.dest_x;
+ m_dma.dest_y = m_p_ram[SM8521_DMY2];
+ m_dma.dest_width = ( m_p_ram[SM8521_LCH] & 0x20 ) ? 50 : 40;
+ m_dma.palette[0] = m_p_ram[SM8521_DMPL] & 0x03;
+ m_dma.palette[1] = ( m_p_ram[SM8521_DMPL] >> 2 ) & 3;
+ m_dma.palette[2] = ( m_p_ram[SM8521_DMPL] >> 4 ) & 3;
+ m_dma.palette[3] = m_p_ram[SM8521_DMPL] >> 6;
+ m_dma.source_mask = 0x1FFF;
+ m_dma.dest_mask = 0x1FFF;
+// logerror("DMA: width %Xx%X, source (%X,%X), dest (%X,%X), transfer_mode %X, banks %X \n", m_dma.width_x, m_dma.width_y, m_dma.source_x, m_dma.source_y, m_dma.dest_x, m_dma.dest_y, m_dma.transfer_mode, m_p_ram[SM8521_DMVP] );
+// logerror( " Palette: %d, %d, %d, %d\n", m_dma.palette[0], m_dma.palette[1], m_dma.palette[2], m_dma.palette[3] );
+ switch( m_dma.transfer_mode )
+ {
+ case 0x00:
+ /* VRAM->VRAM */
+ m_dma.source_bank = &m_p_videoram[(m_p_ram[SM8521_DMVP] & 0x01) ? 0x2000 : 0x0000];
+ m_dma.dest_bank = &m_p_videoram[(m_p_ram[SM8521_DMVP] & 0x02) ? 0x2000 : 0x0000];
+ break;
+ case 0x02:
+ /* ROM->VRAM */
+// logerror( "DMA DMBR = %X\n", m_p_ram[SM8521_DMBR] );
+ m_dma.source_width = 64;
+ m_dma.source_mask = 0x3FFF;
+ if (m_p_ram[SM8521_DMBR] < 16)
+ m_dma.source_bank = m_region_kernel->base() + (m_p_ram[SM8521_DMBR] << 14);
+ else
+ if (m_cart_ptr)
+ m_dma.source_bank = m_cart_ptr + (m_p_ram[SM8521_DMBR] << 14);
+
+ m_dma.dest_bank = &m_p_videoram[(m_p_ram[SM8521_DMVP] & 0x02) ? 0x2000 : 0x0000];
+ break;
+ case 0x04:
+ /* Extend RAM->VRAM */
+ m_dma.source_width = 64;
+ m_dma.source_bank = &m_p_nvram[0x0000];
+ m_dma.dest_bank = &m_p_videoram[(m_p_ram[SM8521_DMVP] & 0x02) ? 0x2000 : 0x0000];
+ break;
+ case 0x06:
+ /* VRAM->Extend RAM */
+ m_dma.source_bank = &m_p_videoram[(m_p_ram[SM8521_DMVP] & 0x01) ? 0x2000 : 0x0000];
+ m_dma.dest_width = 64;
+ m_dma.dest_bank = &m_p_nvram[0x0000];
+ break;
+ }
+ m_dma.source_current = m_dma.source_width * m_dma.source_y;
+ m_dma.source_current += m_dma.source_x >> 2;
+ m_dma.dest_current = m_dma.dest_width * m_dma.dest_y;
+ m_dma.dest_current += m_dma.dest_x >> 2;
+ m_dma.source_line = m_dma.source_current;
+ m_dma.dest_line = m_dma.dest_current;
+ m_dma.state_count = 0;
+
+ unsigned y_count, x_count;
+
+ for( y_count = 0; y_count <= m_dma.width_y; y_count++ )
+ {
+ for( x_count = 0; x_count <= m_dma.width_x; x_count++ )
+ {
+ UINT16 src_addr = m_dma.source_current & m_dma.source_mask;
+ UINT16 dest_addr = m_dma.dest_current & m_dma.dest_mask;
+ UINT8 dest_adj = (3 - (m_dma.dest_x_current & 3)) << 1;
+ UINT8 src_adj = (3 - (m_dma.source_x_current & 3)) << 1;
+
+ /* handle DMA for 1 pixel */
+ // Get new pixel
+ UINT8 source_pixel = (m_dma.source_bank[src_addr] >> src_adj) & 3;
+
+ // If overwrite mode, write new pixel
+ if ( m_dma.overwrite_mode || source_pixel)
+ {
+ // Get 4 pixels and remove the one about to be replaced
+ UINT8 other_pixels = m_dma.dest_bank[dest_addr] & ~(3 << dest_adj);
+ // Get palette of new pixel and place into the hole
+ m_dma.dest_bank[dest_addr] = other_pixels | (m_dma.palette[ source_pixel ] << dest_adj);
+ }
+
+ /* Advance a pixel */
+ if ( m_dma.decrement_x )
+ {
+ m_dma.source_x_current--;
+ if ( ( m_dma.source_x_current & 0x03 ) == 0x03 )
+ m_dma.source_current--;
+ }
+ else
+ {
+ m_dma.source_x_current++;
+ if ( ( m_dma.source_x_current & 0x03 ) == 0x00 )
+ m_dma.source_current++;
+ }
+ m_dma.dest_x_current++;
+ if ( ( m_dma.dest_x_current & 0x03 ) == 0x00 )
+ m_dma.dest_current++;
+ }
+
+ /* Advance a line */
+ m_dma.source_x_current = m_dma.source_x;
+ m_dma.dest_x_current = m_dma.dest_x;
+ if ( m_dma.decrement_y )
+ m_dma.source_line -= m_dma.source_width;
+ else
+ m_dma.source_line += m_dma.source_width;
+ m_dma.source_current = m_dma.source_line;
+ m_dma.dest_line += m_dma.dest_width;
+ m_dma.dest_current = m_dma.dest_line;
+ }
+ m_dma.enabled = 0;
+ m_maincpu->set_input_line(sm8500_cpu_device::DMA_INT, ASSERT_LINE );
+}
+
+WRITE8_MEMBER( gamecom_state::gamecom_update_timers )
+{
+ if ( m_timer[0].enabled )
+ {
+ m_timer[0].state_count += data;
+ while ( m_timer[0].state_count >= m_timer[0].state_limit )
+ {
+ m_timer[0].state_count -= m_timer[0].state_limit;
+ m_p_ram[SM8521_TM0D]++;
+ if ( m_p_ram[SM8521_TM0D] >= m_timer[0].check_value )
+ {
+ m_p_ram[SM8521_TM0D] = 0;
+ m_maincpu->set_input_line(sm8500_cpu_device::TIM0_INT, ASSERT_LINE );
+ }
+ }
+ }
+ if ( m_timer[1].enabled )
+ {
+ m_timer[1].state_count += data;
+ while ( m_timer[1].state_count >= m_timer[1].state_limit )
+ {
+ m_timer[1].state_count -= m_timer[1].state_limit;
+ m_p_ram[SM8521_TM1D]++;
+ if ( m_p_ram[SM8521_TM1D] >= m_timer[1].check_value )
+ {
+ m_p_ram[SM8521_TM1D] = 0;
+ m_maincpu->set_input_line(sm8500_cpu_device::TIM1_INT, ASSERT_LINE );
+ }
+ }
+ }
+}
+
+DRIVER_INIT_MEMBER(gamecom_state,gamecom)
+{
+ m_clock_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(gamecom_state::gamecom_clock_timer_callback),this));
+ m_p_ram = m_region_maincpu->base(); // required here because pio_w gets called before machine_reset
+}
+
+int gamecom_state::common_load(device_image_interface &image, generic_slot_device *slot)
+{
+ UINT32 size = slot->common_get_size("rom");
+ UINT32 load_offset = 0;
+
+ if (size != 0x008000 && size != 0x040000 && size != 0x080000
+ && size != 0x100000 && size != 0x1c0000 && size != 0x200000)
+ {
+ image.seterror(IMAGE_ERROR_UNSPECIFIED, "Unsupported cartridge size");
+ return IMAGE_INIT_FAIL;
+ }
+
+ if (size == 0x1c0000)
+ load_offset = 0x40000;
+
+ // in order to simplify banked access from the driver, we always allocate 0x200000,
+ slot->rom_alloc(0x200000, GENERIC_ROM8_WIDTH, ENDIANNESS_LITTLE);
+ // we load what we have
+ slot->common_load_rom(slot->get_rom_base() + load_offset, size, "rom");
+ // and then we mirror the content, instead of masking out larger accesses
+ UINT8 *crt = slot->get_rom_base();
+ if (size < 0x010000) { memcpy(crt + 0x008000, crt, 0x008000); } /* ->64KB */
+ if (size < 0x020000) { memcpy(crt + 0x010000, crt, 0x010000); } /* ->128KB */
+ if (size < 0x040000) { memcpy(crt + 0x020000, crt, 0x020000); } /* ->256KB */
+ if (size < 0x080000) { memcpy(crt + 0x040000, crt, 0x040000); } /* ->512KB */
+ if (size < 0x100000) { memcpy(crt + 0x080000, crt, 0x080000); } /* ->1MB */
+ if (size < 0x1c0000) { memcpy(crt + 0x100000, crt, 0x100000); } /* -> >=1.8MB */
+
+ return IMAGE_INIT_PASS;
+}
+
+DEVICE_IMAGE_LOAD_MEMBER( gamecom_state, gamecom_cart1 )
+{
+ return common_load(image, m_cart1);
+}
+
+DEVICE_IMAGE_LOAD_MEMBER( gamecom_state, gamecom_cart2 )
+{
+ return common_load(image, m_cart2);
+}