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#include "emu.h"
#include "cpu/m6809/m6809.h"
#include "machine/6522via.h"
#include "includes/beezer.h"
INTERRUPT_GEN( beezer_interrupt )
{
beezer_state *state = device->machine().driver_data<beezer_state>();
via6522_device *via_0 = device->machine().device<via6522_device>("via6522_0");
state->m_scanline = (state->m_scanline + 1) % 0x80;
via_0->write_ca2((state->m_scanline & 0x10) ? 1 : 0);
if ((state->m_scanline & 0x78) == 0x78)
device_set_input_line(device, M6809_FIRQ_LINE, ASSERT_LINE);
else
device_set_input_line(device, M6809_FIRQ_LINE, CLEAR_LINE);
}
SCREEN_UPDATE( beezer )
{
beezer_state *state = screen->machine().driver_data<beezer_state>();
UINT8 *videoram = state->m_videoram;
int x,y;
for (y = cliprect->min_y; y <= cliprect->max_y; y+=2)
for (x = cliprect->min_x; x <= cliprect->max_x; x++)
{
*BITMAP_ADDR16(bitmap, y+1, x) = videoram[0x80*y+x] & 0x0f;
*BITMAP_ADDR16(bitmap, y, x) = videoram[0x80*y+x] >> 4;
}
return 0;
}
WRITE8_HANDLER( beezer_map_w )
{
/*
bit 7 -- 330 ohm resistor -- BLUE
-- 560 ohm resistor -- BLUE
-- 330 ohm resistor -- GREEN
-- 560 ohm resistor -- GREEN
-- 1.2 kohm resistor -- GREEN
-- 330 ohm resistor -- RED
-- 560 ohm resistor -- RED
bit 0 -- 1.2 kohm resistor -- RED
*/
int r, g, b, bit0, bit1, bit2;
/* red component */
bit0 = (data >> 0) & 0x01;
bit1 = (data >> 1) & 0x01;
bit2 = (data >> 2) & 0x01;
r = 0x26 * bit0 + 0x50 * bit1 + 0x89 * bit2;
/* green component */
bit0 = (data >> 3) & 0x01;
bit1 = (data >> 4) & 0x01;
bit2 = (data >> 5) & 0x01;
g = 0x26 * bit0 + 0x50 * bit1 + 0x89 * bit2;
/* blue component */
bit0 = (data >> 6) & 0x01;
bit1 = (data >> 7) & 0x01;
b = 0x5f * bit0 + 0xa0 * bit1;
palette_set_color(space->machine(), offset, MAKE_RGB(r, g, b));
}
READ8_HANDLER( beezer_line_r )
{
beezer_state *state = space->machine().driver_data<beezer_state>();
return (state->m_scanline & 0xfe) << 1;
}
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