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#include "driver.h"
#include "cpu/m6809/m6809.h"
#include "machine/6522via.h"
static int scanline=0;
INTERRUPT_GEN( beezer_interrupt )
{
scanline = (scanline + 1) % 0x80;
via_0_ca2_w (0, scanline & 0x10);
if ((scanline & 0x78) == 0x78)
cpunum_set_input_line(0, M6809_FIRQ_LINE, ASSERT_LINE);
else
cpunum_set_input_line(0, M6809_FIRQ_LINE, CLEAR_LINE);
}
VIDEO_UPDATE( beezer )
{
int x,y;
for (y = machine->screen[0].visarea.min_y; y <= machine->screen[0].visarea.max_y; y+=2)
{
for (x = machine->screen[0].visarea.min_x; x <= machine->screen[0].visarea.max_x; x++)
{
*BITMAP_ADDR16(bitmap, y+1, x) = machine->pens[videoram[0x80*y+x] & 0x0f];
*BITMAP_ADDR16(bitmap, y, x) = machine->pens[(videoram[0x80*y+x] >> 4)& 0x0f];
}
}
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(Machine, offset, MAKE_RGB(r, g, b));
}
READ8_HANDLER( beezer_line_r )
{
return (scanline & 0xfe) << 1;
}
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