1 // license:GPL-2.0+
2 // copyright-holders:Juergen Buchmueller
3 /****************************************************************************
4 *
5 * warpwarp.cpp
6 *
7 * sound driver
8 * juergen buchmueller <pullmoll@t-online.de>, jan 2000
9 *
10 ****************************************************************************/
11
12 #include "emu.h"
13 #include "audio/warpwarp.h"
14
15
16 DEFINE_DEVICE_TYPE(WARPWARP_SOUND, warpwarp_sound_device, "warpwarp_sound", "Warp Warp Custom Sound")
17
warpwarp_sound_device(const machine_config & mconfig,const char * tag,device_t * owner,uint32_t clock)18 warpwarp_sound_device::warpwarp_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
19 : device_t(mconfig, WARPWARP_SOUND, tag, owner, clock),
20 device_sound_interface(mconfig, *this),
21 m_decay(nullptr),
22 m_channel(nullptr),
23 m_sound_latch(0),
24 m_music1_latch(0),
25 m_music2_latch(0),
26 m_sound_signal(0),
27 m_sound_volume(0),
28 m_sound_volume_timer(nullptr),
29 m_music_signal(0),
30 m_music_volume(0),
31 m_music_volume_timer(nullptr),
32 m_noise(0),
33 m_vcarry(0),
34 m_vcount(0),
35 m_mcarry(0),
36 m_mcount(0)
37 {
38 }
39
40
41
42 //-------------------------------------------------
43 // device_start - device-specific startup
44 //-------------------------------------------------
45
device_start()46 void warpwarp_sound_device::device_start()
47 {
48 m_decay = std::make_unique<int16_t[]>(32768);
49
50 for (int i = 0; i < 0x8000; i++)
51 m_decay[0x7fff - i] = (int16_t) (0x7fff/exp(1.0*i/4096));
52
53 m_clock_16h = clock() / 3 / 2 / 16;
54 m_clock_1v = clock() / 3 / 2 / 384;
55 m_channel = stream_alloc(0, 1, m_clock_16h);
56
57 m_sound_volume_timer = timer_alloc(TIMER_SOUND_VOLUME_DECAY);
58 m_music_volume_timer = timer_alloc(TIMER_MUSIC_VOLUME_DECAY);
59
60 save_item(NAME(m_sound_latch));
61 save_item(NAME(m_music1_latch));
62 save_item(NAME(m_music2_latch));
63 save_item(NAME(m_sound_signal));
64 save_item(NAME(m_sound_volume));
65 save_item(NAME(m_music_signal));
66 save_item(NAME(m_music_volume));
67 save_item(NAME(m_noise));
68 save_item(NAME(m_vcarry));
69 save_item(NAME(m_vcount));
70 save_item(NAME(m_mcarry));
71 save_item(NAME(m_mcount));
72 }
73
device_timer(emu_timer & timer,device_timer_id id,int param,void * ptr)74 void warpwarp_sound_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
75 {
76 switch (id)
77 {
78 case TIMER_SOUND_VOLUME_DECAY:
79 if (--m_sound_volume < 0)
80 m_sound_volume = 0;
81 break;
82
83 case TIMER_MUSIC_VOLUME_DECAY:
84 if (--m_music_volume < 0)
85 m_music_volume = 0;
86 break;
87
88 default:
89 throw emu_fatalerror("Unknown id in warpwarp_sound_device::device_timer");
90 }
91 }
92
sound_w(u8 data)93 void warpwarp_sound_device::sound_w(u8 data)
94 {
95 m_channel->update();
96 m_sound_latch = data & 0x0f;
97 m_sound_volume = 0x7fff; /* set sound_volume */
98 m_noise = 0x0000; /* reset noise shifter */
99
100 /* faster decay enabled? */
101 if( m_sound_latch & 8 )
102 {
103 /*
104 * R85(?) is 10k, Rb is 0, C92 is 1uF
105 * charge time t1 = 0.693 * (R24 + Rb) * C57 -> 0.22176s
106 * discharge time t2 = 0.693 * (Rb) * C57 -> 0
107 * C90(?) is only charged via D17 (1N914), no discharge!
108 * Decay:
109 * discharge C90(?) (1uF) through R13||R14 (22k||47k)
110 * 0.639 * 15k * 1uF -> 0.9585s
111 */
112 attotime period = attotime::from_hz(32768) * 95850 / 100000;
113 m_sound_volume_timer->adjust(period, 0, period);
114 }
115 else
116 {
117 /*
118 * discharge only after R93 (100k) and through the 10k
119 * potentiometerin the amplifier section.
120 * 0.639 * 110k * 1uF -> 7.0290s
121 * ...but this is not very realistic for the game sound :(
122 * maybe there _is_ a discharge through the diode D17?
123 */
124 //attotime period = attotime::from_hz(32768) * 702900 / 100000;
125 attotime period = attotime::from_hz(32768) * 191700 / 100000;
126 m_sound_volume_timer->adjust(period, 0, period);
127 }
128 }
129
music1_w(u8 data)130 void warpwarp_sound_device::music1_w(u8 data)
131 {
132 m_channel->update();
133 m_music1_latch = data & 0x3f;
134 }
135
music2_w(u8 data)136 void warpwarp_sound_device::music2_w(u8 data)
137 {
138 m_channel->update();
139 m_music2_latch = data & 0x3f;
140 m_music_volume = 0x7fff;
141 /* fast decay enabled? */
142 if( m_music2_latch & 0x10 )
143 {
144 /*
145 * Ra (R83?) is 10k, Rb is 0, C92 is 1uF
146 * charge time t1 = 0.693 * (Ra + Rb) * C -> 0.22176s
147 * discharge time is (nearly) zero, because Rb is zero
148 * C95(?) is only charged via D17, not discharged!
149 * Decay:
150 * discharge C95(?) (10uF) through R13||R14 (22k||47k)
151 * 0.639 * 15k * 10uF -> 9.585s
152 * ...I'm sure this is off by one number of magnitude :/
153 */
154 attotime period = attotime::from_hz(32768) * 95850 / 100000;
155 m_music_volume_timer->adjust(period, 0, period);
156 }
157 else
158 {
159 /*
160 * discharge through R14 (47k),
161 * discharge C95(?) (10uF) through R14 (47k)
162 * 0.639 * 47k * 10uF -> 30.033s
163 */
164 //attotime period = attotime::from_hz(32768) * 3003300 / 100000;
165 attotime period = attotime::from_hz(32768) * 300330 / 100000;
166 m_music_volume_timer->adjust(period, 0, period);
167 }
168
169 }
170
171 //-------------------------------------------------
172 // sound_stream_update - handle a stream update
173 //-------------------------------------------------
174
sound_stream_update(sound_stream & stream,std::vector<read_stream_view> const & inputs,std::vector<write_stream_view> & outputs)175 void warpwarp_sound_device::sound_stream_update(sound_stream &stream, std::vector<read_stream_view> const &inputs, std::vector<write_stream_view> &outputs)
176 {
177 auto &buffer = outputs[0];
178
179 for (int sampindex = 0; sampindex < buffer.samples(); sampindex++)
180 {
181 buffer.put_int(sampindex, m_sound_signal + m_music_signal, 32768 * 2);
182
183 /*
184 * The music signal is selected at a rate of 2H (1.536MHz) from the
185 * four bits of a 4 bit binary counter which is clocked with 16H,
186 * which is 192kHz, and is divided by 4 times (64 - music1_latch).
187 * 0 = 256 steps -> 750 Hz
188 * 1 = 252 steps -> 761.9 Hz
189 * ...
190 * 32 = 128 steps -> 1500 Hz
191 * ...
192 * 48 = 64 steps -> 3000 Hz
193 * ...
194 * 63 = 4 steps -> 48 kHz
195 */
196
197 m_mcarry -= m_clock_16h / (4 * (64 - m_music1_latch));
198 while( m_mcarry < 0 )
199 {
200 m_mcarry += m_clock_16h;
201 m_mcount++;
202 m_music_signal = (m_mcount & ~m_music2_latch & 15) ? m_decay[m_music_volume] : 0;
203 /* override by noise gate? */
204 if( (m_music2_latch & 32) && (m_noise & 0x8000) )
205 m_music_signal = m_decay[m_music_volume];
206 }
207
208 /* clock 1V = 8kHz */
209 m_vcarry -= m_clock_1v;
210 while (m_vcarry < 0)
211 {
212 m_vcarry += m_clock_16h;
213 m_vcount++;
214
215 /* noise is clocked with raising edge of 2V */
216 if ((m_vcount & 3) == 2)
217 {
218 /* bit0 = bit0 ^ !bit10 */
219 if ((m_noise & 1) == ((m_noise >> 10) & 1))
220 m_noise = (m_noise << 1) | 1;
221 else
222 m_noise = m_noise << 1;
223 }
224
225 switch (m_sound_latch & 7)
226 {
227 case 0: /* 4V */
228 m_sound_signal = (m_vcount & 0x04) ? m_decay[m_sound_volume] : 0;
229 break;
230 case 1: /* 8V */
231 m_sound_signal = (m_vcount & 0x08) ? m_decay[m_sound_volume] : 0;
232 break;
233 case 2: /* 16V */
234 m_sound_signal = (m_vcount & 0x10) ? m_decay[m_sound_volume] : 0;
235 break;
236 case 3: /* 32V */
237 m_sound_signal = (m_vcount & 0x20) ? m_decay[m_sound_volume] : 0;
238 break;
239 case 4: /* TONE1 */
240 m_sound_signal = !(m_vcount & 0x01) && !(m_vcount & 0x10) ? m_decay[m_sound_volume] : 0;
241 break;
242 case 5: /* TONE2 */
243 m_sound_signal = !(m_vcount & 0x02) && !(m_vcount & 0x20) ? m_decay[m_sound_volume] : 0;
244 break;
245 case 6: /* TONE3 */
246 m_sound_signal = !(m_vcount & 0x04) && !(m_vcount & 0x40) ? m_decay[m_sound_volume] : 0;
247 break;
248 default: /* NOISE */
249 /* QH of 74164 #4V */
250 m_sound_signal = (m_noise & 0x8000) ? m_decay[m_sound_volume] : 0;
251 }
252
253 }
254 }
255 }
256