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
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
|
// license:BSD-3-Clause
// copyright-holders:Zsolt Vasvari
/***************************************************************************
Exidy Car Polo hardware
driver by Zsolt Vasvari
****************************************************************************/
#include "emu.h"
#include "cpu/m6502/m6502.h"
#include "machine/6821pia.h"
#include "includes/carpolo.h"
/*************************************
*
* Interrupt system
*
*************************************/
/* the interrupt system consists of a 74148 priority encoder
with the following interrupt priorites. A lower number
indicates a lower priority (coins handled first):
7 - player 1 coin
6 - player 2 coin
5 - player 3 coin
4 - player 4 coin
3 - ball/screen object collision
2 - car/car collision
1 - car/goal collision
0 - timer (bit 4=0, bit 6=0)
0 - car/ball collision (bit 4=0, bit 6=1)
0 - car/border (bit 4=1, bit 6=1)
After the interrupt is serviced, the code clears the
priority encoder's appropriate line by pulling it HI. This
can trigger another interrupt immediately if there were
lower priority lines LO.
The four coin inputs are latched via 7474 flip-flop's. */
#define COIN1_PRIORITY_LINE 7
#define COIN2_PRIORITY_LINE 6
#define COIN3_PRIORITY_LINE 5
#define COIN4_PRIORITY_LINE 4
#define BALL_SCREEN_PRIORITY_LINE 3
#define CAR_CAR_PRIORITY_LINE 2
#define CAR_GOAL_PRIORITY_LINE 1
#define PRI0_PRIORTITY_LINE 0
/* priority 0 controls three different things */
#define TIMER_EXTRA_BITS 0x00
#define CAR_BALL_EXTRA_BITS 0x40
#define CAR_BORDER_EXTRA_BITS 0x50
void carpolo_state::ttl74148_3s_cb(uint8_t data)
{
m_maincpu->set_input_line(M6502_IRQ_LINE, m_ttl74148_3s->output_valid_r() ? CLEAR_LINE : ASSERT_LINE);
}
/* the outputs of the flip-flops are connected to the priority encoder */
WRITE_LINE_MEMBER(carpolo_state::ttl7474_2s_1_q_cb)
{
m_ttl74148_3s->input_line_w(COIN1_PRIORITY_LINE, state);
m_ttl74148_3s->update();
}
WRITE_LINE_MEMBER(carpolo_state::ttl7474_2s_2_q_cb)
{
m_ttl74148_3s->input_line_w(COIN2_PRIORITY_LINE, state);
m_ttl74148_3s->update();
}
WRITE_LINE_MEMBER(carpolo_state::ttl7474_2u_1_q_cb)
{
m_ttl74148_3s->input_line_w(COIN3_PRIORITY_LINE, state);
m_ttl74148_3s->update();
}
WRITE_LINE_MEMBER(carpolo_state::ttl7474_2u_2_q_cb)
{
m_ttl74148_3s->input_line_w(COIN4_PRIORITY_LINE, state);
m_ttl74148_3s->update();
}
void carpolo_state::generate_ball_screen_interrupt(uint8_t cause)
{
m_ball_screen_collision_cause = cause;
m_ttl74148_3s->input_line_w(BALL_SCREEN_PRIORITY_LINE, 0);
m_ttl74148_3s->update();
}
void carpolo_state::generate_car_car_interrupt(int car1, int car2)
{
m_car_car_collision_cause = ~((1 << (3 - car1)) | (1 << (3 - car2)));
m_ttl74148_3s->input_line_w(CAR_CAR_PRIORITY_LINE, 0);
m_ttl74148_3s->update();
}
void carpolo_state::generate_car_goal_interrupt(int car, int right_goal)
{
m_car_goal_collision_cause = car | (right_goal ? 0x08 : 0x00);
m_ttl74148_3s->input_line_w(CAR_GOAL_PRIORITY_LINE, 0);
m_ttl74148_3s->update();
}
void carpolo_state::generate_car_ball_interrupt(int car, int car_x, int car_y)
{
m_car_ball_collision_cause = car;
m_car_ball_collision_x = car_x;
m_car_ball_collision_y = car_y;
m_priority_0_extension = CAR_BALL_EXTRA_BITS;
m_ttl74148_3s->input_line_w(PRI0_PRIORTITY_LINE, 0);
m_ttl74148_3s->update();
}
void carpolo_state::generate_car_border_interrupt(int car, int horizontal_border)
{
m_car_border_collision_cause = car | (horizontal_border ? 0x04 : 0x00);
m_priority_0_extension = CAR_BORDER_EXTRA_BITS;
m_ttl74148_3s->input_line_w(PRI0_PRIORTITY_LINE, 0);
m_ttl74148_3s->update();
}
uint8_t carpolo_state::ball_screen_collision_cause_r()
{
/* bit 0 - 0=ball collided with border
bit 1 - 0=ball collided with goal
bit 2 - 0=ball collided with score area
bit 3 - which goal/score collided (0=left, 1=right) */
return m_ball_screen_collision_cause;
}
uint8_t carpolo_state::car_ball_collision_x_r()
{
/* the x coordinate of the colliding pixel */
return m_car_ball_collision_x;
}
uint8_t carpolo_state::car_ball_collision_y_r()
{
/* the y coordinate of the colliding pixel */
return m_car_ball_collision_y;
}
uint8_t carpolo_state::car_car_collision_cause_r()
{
/* bit 0 - car 4 collided
bit 1 - car 3 collided
bit 2 - car 2 collided
bit 3 - car 1 collided */
return m_car_car_collision_cause;
}
uint8_t carpolo_state::car_goal_collision_cause_r()
{
/* bit 0-1 - which car collided
bit 2 - horizontal timing bit 1TEC4 (not accessed)
bit 3 - which goal collided (0=left, 1=right) */
return m_car_goal_collision_cause;
}
uint8_t carpolo_state::car_ball_collision_cause_r()
{
/* bit 0-1 - which car collided
bit 2-3 - unconnected */
return m_car_ball_collision_cause;
}
uint8_t carpolo_state::car_border_collision_cause_r()
{
/* bit 0-1 - which car collided
bit 2 - 0=vertical border, 1=horizontal border */
return m_car_border_collision_cause;
}
uint8_t carpolo_state::interrupt_cause_r()
{
/* the output of the 148 goes to bits 1-3 (which is priority ^ 7) */
return (m_ttl74148_3s->output_r() << 1) | m_priority_0_extension;
}
void carpolo_state::timer_tick()
{
/* cause the timer interrupt */
m_ttl74148_3s->input_line_w(PRI0_PRIORTITY_LINE, 0);
m_priority_0_extension = TIMER_EXTRA_BITS;
m_ttl74148_3s->update();
/* check the coins here as well - they drive the clock of the flip-flops */
uint8_t port_value = m_in[0]->read();
m_ttl7474_2s_1->clock_w((port_value & 0x01) >> 0);
m_ttl7474_2s_2->clock_w((port_value & 0x02) >> 1);
m_ttl7474_2u_1->clock_w((port_value & 0x04) >> 2);
m_ttl7474_2u_2->clock_w((port_value & 0x08) >> 3);
/* read the steering controls */
for (int player = 0; player < 4; player++)
{
ttl7474_device *movement_flip_flop;
ttl7474_device *dir_flip_flop;
switch (player)
{
default:
case 0: movement_flip_flop = m_ttl7474_1f_1; dir_flip_flop = m_ttl7474_1f_2; break;
case 1: movement_flip_flop = m_ttl7474_1d_1; dir_flip_flop = m_ttl7474_1d_2; break;
case 2: movement_flip_flop = m_ttl7474_1c_1; dir_flip_flop = m_ttl7474_1c_2; break;
case 3: movement_flip_flop = m_ttl7474_1a_1; dir_flip_flop = m_ttl7474_1a_2; break;
}
port_value = m_dial[player]->read();
if (port_value != m_last_wheel_value[player])
{
/* set the movement direction */
dir_flip_flop->d_w(((port_value - m_last_wheel_value[player]) & 0x80) ? 1 : 0);
m_last_wheel_value[player] = port_value;
}
/* as the wheel moves, both flip-flops are clocked */
movement_flip_flop->clock_w(port_value & 0x01);
dir_flip_flop->clock_w( port_value & 0x01);
}
/* finally read the accelerator pedals */
port_value = m_pedals->read();
// one line indicates if the pedal is pressed and the other
// how much, resulting in only two different possible levels
m_ttl74153_1k->i0a_w(BIT(port_value, 0) | BIT(port_value, 1));
m_ttl74153_1k->i1a_w(BIT(port_value, 2) | BIT(port_value, 3));
m_ttl74153_1k->i2a_w(BIT(port_value, 4) | BIT(port_value, 5));
m_ttl74153_1k->i3a_w(BIT(port_value, 6) | BIT(port_value, 7));
m_ttl74153_1k->i0b_w(BIT(port_value, 1));
m_ttl74153_1k->i1b_w(BIT(port_value, 3));
m_ttl74153_1k->i2b_w(BIT(port_value, 5));
m_ttl74153_1k->i3b_w(BIT(port_value, 7));
}
// FIXME: Remove trampolines
WRITE_LINE_MEMBER(carpolo_state::coin1_interrupt_clear_w)
{
m_ttl7474_2s_1->clear_w(state);
}
WRITE_LINE_MEMBER(carpolo_state::coin2_interrupt_clear_w)
{
m_ttl7474_2s_2->clear_w(state);
}
WRITE_LINE_MEMBER(carpolo_state::coin3_interrupt_clear_w)
{
m_ttl7474_2u_1->clear_w(state);
}
WRITE_LINE_MEMBER(carpolo_state::coin4_interrupt_clear_w)
{
m_ttl7474_2u_2->clear_w(state);
}
void carpolo_state::ball_screen_interrupt_clear_w(uint8_t data)
{
m_ttl74148_3s->input_line_w(BALL_SCREEN_PRIORITY_LINE, 1);
m_ttl74148_3s->update();
}
void carpolo_state::car_car_interrupt_clear_w(uint8_t data)
{
m_ttl74148_3s->input_line_w(CAR_CAR_PRIORITY_LINE, 1);
m_ttl74148_3s->update();
}
void carpolo_state::car_goal_interrupt_clear_w(uint8_t data)
{
m_ttl74148_3s->input_line_w(CAR_GOAL_PRIORITY_LINE, 1);
m_ttl74148_3s->update();
}
void carpolo_state::car_ball_interrupt_clear_w(uint8_t data)
{
m_ttl74148_3s->input_line_w(PRI0_PRIORTITY_LINE, 1);
m_ttl74148_3s->update();
}
void carpolo_state::car_border_interrupt_clear_w(uint8_t data)
{
m_ttl74148_3s->input_line_w(PRI0_PRIORTITY_LINE, 1);
m_ttl74148_3s->update();
}
void carpolo_state::timer_interrupt_clear_w(uint8_t data)
{
m_ttl74148_3s->input_line_w(PRI0_PRIORTITY_LINE, 1);
m_ttl74148_3s->update();
}
/*************************************
*
* Input port handling
*
*************************************/
WRITE_LINE_MEMBER( carpolo_state::ls153_za_w )
{
m_ls153_za = state;
}
WRITE_LINE_MEMBER( carpolo_state::ls153_zb_w )
{
m_ls153_zb = state;
}
void carpolo_state::pia_0_port_a_w(uint8_t data)
{
/* bit 0 - Coin counter
bit 1 - Player 4 crash sound
bit 2 - Player 3 crash sound
bit 3 - Clear steering wheel logic
bit 4 - Player 2 crash sound
bit 5 - Score pulse sound
bit 6 - Player 1 crash sound
bit 7 - Ball hit pulse sound */
machine().bookkeeping().coin_counter_w(0, data & 0x01);
m_ttl7474_1f_1->clear_w((data & 0x08) >> 3);
m_ttl7474_1d_1->clear_w((data & 0x08) >> 3);
m_ttl7474_1c_1->clear_w((data & 0x08) >> 3);
m_ttl7474_1a_1->clear_w((data & 0x08) >> 3);
}
void carpolo_state::pia_0_port_b_w(uint8_t data)
{
/* bit 0 - Strobe speed bits sound
bit 1 - Speed bit 0 sound
bit 2 - Speed bit 1 sound
bit 3 - Speed bit 2 sound
bit 6 - Select pedal 0
bit 7 - Select pdeal 1 */
m_ttl74153_1k->s0_w(BIT(data, 6));
m_ttl74153_1k->s1_w(BIT(data, 7));
}
uint8_t carpolo_state::pia_0_port_b_r()
{
/* bit 4 - Pedal bit 0
bit 5 - Pedal bit 1 */
return (m_ls153_za << 5) | (m_ls153_zb << 4);
}
uint8_t carpolo_state::pia_1_port_a_r()
{
uint8_t ret;
/* bit 0 - Player 4 steering input (left or right)
bit 1 - Player 3 steering input (left or right)
bit 2 - Player 2 steering input (left or right)
bit 3 - Player 1 steering input (left or right)
bit 4 - Player 4 forward/reverse input
bit 5 - Player 3 forward/reverse input
bit 6 - Player 2 forward/reverse input
bit 7 - Player 1 forward/reverse input */
ret = (m_ttl7474_1a_2->output_r() ? 0x01 : 0x00) |
(m_ttl7474_1c_2->output_r() ? 0x02 : 0x00) |
(m_ttl7474_1d_2->output_r() ? 0x04 : 0x00) |
(m_ttl7474_1f_2->output_r() ? 0x08 : 0x00) |
(m_in[2]->read() & 0xf0);
return ret;
}
uint8_t carpolo_state::pia_1_port_b_r()
{
uint8_t ret;
/* bit 4 - Player 4 steering input (wheel moving or stopped)
bit 5 - Player 3 steering input (wheel moving or stopped)
bit 6 - Player 2 steering input (wheel moving or stopped)
bit 7 - Player 1 steering input (wheel moving or stopped) */
ret = (m_ttl7474_1a_1->output_r() ? 0x10 : 0x00) |
(m_ttl7474_1c_1->output_r() ? 0x20 : 0x00) |
(m_ttl7474_1d_1->output_r() ? 0x40 : 0x00) |
(m_ttl7474_1f_1->output_r() ? 0x80 : 0x00);
return ret;
}
void carpolo_state::machine_start()
{
save_item(NAME(m_ball_screen_collision_cause));
save_item(NAME(m_car_ball_collision_x));
save_item(NAME(m_car_ball_collision_y));
save_item(NAME(m_car_car_collision_cause));
save_item(NAME(m_car_goal_collision_cause));
save_item(NAME(m_car_ball_collision_cause));
save_item(NAME(m_car_border_collision_cause));
save_item(NAME(m_priority_0_extension));
save_item(NAME(m_last_wheel_value));
}
void carpolo_state::machine_reset()
{
/* set up the priority encoder */
m_ttl74148_3s->enable_input_w(0); /* always enabled */
/* set up the coin handling flip-flops */
m_ttl7474_2s_1->d_w (1);
m_ttl7474_2s_1->preset_w(1);
m_ttl7474_2s_2->d_w (1);
m_ttl7474_2s_2->preset_w(1);
m_ttl7474_2u_1->d_w (1);
m_ttl7474_2u_1->preset_w(1);
m_ttl7474_2u_2->d_w (1);
m_ttl7474_2u_2->preset_w(1);
/* set up the steering handling flip-flops */
m_ttl7474_1f_1->d_w (1);
m_ttl7474_1f_1->preset_w(1);
m_ttl7474_1f_2->clear_w (1);
m_ttl7474_1f_2->preset_w(1);
m_ttl7474_1d_1->d_w (1);
m_ttl7474_1d_1->preset_w(1);
m_ttl7474_1d_2->clear_w (1);
m_ttl7474_1d_2->preset_w(1);
m_ttl7474_1c_1->d_w (1);
m_ttl7474_1c_1->preset_w(1);
m_ttl7474_1c_2->clear_w (1);
m_ttl7474_1c_2->preset_w(1);
m_ttl7474_1a_1->d_w (1);
m_ttl7474_1a_1->preset_w(1);
m_ttl7474_1a_2->clear_w (1);
m_ttl7474_1a_2->preset_w(1);
}
|