1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
#include "emu.h"
#include "cpu/m6809/m6809.h"
#include "machine/6522via.h"
#include "includes/beezer.h"
TIMER_DEVICE_CALLBACK( beezer_interrupt )
{
int scanline = param;
// beezer_state *state = timer.machine().driver_data<beezer_state>();
via6522_device *via_0 = timer.machine().device<via6522_device>("via6522_0");
via_0->write_ca2((scanline & 0x20) ? 1 : 0);
#if 0
if (scanline == 240) // actually unused by the game! (points to a tight loop)
device_set_input_line(state->m_maincpu, M6809_FIRQ_LINE, ASSERT_LINE);
else
device_set_input_line(state->m_maincpu, M6809_FIRQ_LINE, CLEAR_LINE);
#endif
}
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++)
for (x = cliprect->min_x; x <= cliprect->max_x; x+=2)
{
*BITMAP_ADDR16(bitmap, y, x+1) = videoram[0x80*x+y] & 0x0f;
*BITMAP_ADDR16(bitmap, y, x+0) = videoram[0x80*x+y] >> 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 )
{
return space->machine().primary_screen->vpos();
// Note: was (state->m_scanline & 0xfe) << 1; with scanline % 128
}
|