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/**************************************************************************
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**************************************************************************
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DEVICE_START(votrax)- Start emulation, load samples from Votrax subdirectory
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votrax_w - Write data to votrax port
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votrax_status_r - Return busy status (-1 = busy)
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If you need to alter the base frequency (i.e. Qbert) then just alter
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the variable VotraxBaseFrequency, this is defaulted to 8000
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**************************************************************************/
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/***************************************************************************
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Simple VOTRAX SC-01 simulator based on sample fragments.
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****************************************************************************
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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* Neither the name 'MAME' nor the names of its contributors may be
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used to endorse or promote products derived from this software
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without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
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INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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***************************************************************************/
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#include "votrax.h"
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typedef struct _votrax_state votrax_state;
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int frequency; /* Some games (Qbert) change this */
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sound_stream * channel;
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loaded_sample *sample;
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loaded_samples *samples;
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INLINE votrax_state *get_safe_token(device_t *device)
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assert(device != NULL);
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assert(device->type() == VOTRAX);
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return (votrax_state *)downcast<legacy_device_base *>(device)->token();
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#define FRAC_ONE (1 << FRAC_BITS)
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#define FRAC_MASK (FRAC_ONE - 1)
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/****************************************************************************
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* 64 Phonemes - currently 1 sample per phoneme, will be combined sometime!
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****************************************************************************/
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static const char *const VotraxTable[65] =
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"EH3","EH2","EH1","PA0","DT" ,"A1" ,"A2" ,"ZH",
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"AH2","I3" ,"I2" ,"I1" ,"M" ,"N" ,"B" ,"V",
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"CH" ,"SH" ,"Z" ,"AW1","NG" ,"AH1","OO1","OO",
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"L" ,"K" ,"J" ,"H" ,"G" ,"F" ,"D" ,"S",
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"A" ,"AY" ,"Y1" ,"UH3","AH" ,"P" ,"O" ,"I",
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"U" ,"Y" ,"T" ,"R" ,"E" ,"W" ,"AE" ,"AE1",
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"AW2","UH2","UH1","UH" ,"O2" ,"O1" ,"IU" ,"U1",
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"THV","TH" ,"ER" ,"EH" ,"E1" ,"AW" ,"PA1","STOP",
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static STREAM_UPDATE( votrax_update_sound )
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votrax_state *info = (votrax_state*) param;
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stream_sample_t *buffer = outputs[0];
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/* load some info locally */
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UINT32 pos = info->pos;
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UINT32 frac = info->frac;
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UINT32 step = info->step;
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UINT32 length = info->sample->length;
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INT16 *sample = info->sample->data;
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/* do a linear interp on the sample */
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INT32 sample1 = sample[pos];
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INT32 sample2 = sample[(pos + 1) % length];
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INT32 fracmult = frac >> (FRAC_BITS - 14);
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*buffer++ = ((0x4000 - fracmult) * sample1 + fracmult * sample2) >> 14;
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pos += frac >> FRAC_BITS;
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frac = frac & ((1 << FRAC_BITS) - 1);
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/* handle looping/ending */
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/* push position back out */
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static DEVICE_START( votrax )
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votrax_state *votrax = get_safe_token(device);
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votrax->device = device;
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votrax->samples = readsamples(device->machine(),VotraxTable,"votrax");
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votrax->frequency = 8000;
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votrax->volume = 230;
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votrax->channel = device->machine().sound().stream_alloc(*device, 0, 1, device->machine().sample_rate(), votrax, votrax_update_sound);
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votrax->sample = NULL;
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WRITE8_DEVICE_HANDLER( votrax_w )
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votrax_state *info = get_safe_token(device);
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int Phoneme,Intonation;
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info->channel->update();
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Phoneme = data & 0x3F;
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Intonation = data >> 6;
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logerror("Speech : %s at intonation %d\n",VotraxTable[Phoneme],Intonation);
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if(info->samples->sample[Phoneme].data)
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info->sample = &info->samples->sample[Phoneme];
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info->step = ((INT64)(info->sample->frequency + (256*Intonation)) << FRAC_BITS) / info->device->machine().sample_rate();
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info->channel->set_output_gain(0, (info->volume + (8*Intonation)*100/255) / 100.0);
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int votrax_status_r(device_t *device)
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votrax_state *info = get_safe_token(device);
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info->channel->update();
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return (info->sample != NULL);
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/**************************************************************************
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**************************************************************************/
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DEVICE_GET_INFO( votrax )
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/* --- the following bits of info are returned as 64-bit signed integers --- */
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case DEVINFO_INT_TOKEN_BYTES: info->i = sizeof(votrax_state); break;
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/* --- the following bits of info are returned as pointers to data or functions --- */
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case DEVINFO_FCT_START: info->start = DEVICE_START_NAME( votrax ); break;
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case DEVINFO_FCT_STOP: /* Nothing */ break;
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case DEVINFO_FCT_RESET: /* Nothing */ break;
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/* --- the following bits of info are returned as NULL-terminated strings --- */
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case DEVINFO_STR_NAME: strcpy(info->s, "Votrax SC-01"); break;
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case DEVINFO_STR_FAMILY: strcpy(info->s, "Votrax speech"); break;
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case DEVINFO_STR_VERSION: strcpy(info->s, "1.0"); break;
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case DEVINFO_STR_SOURCE_FILE: strcpy(info->s, __FILE__); break;
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case DEVINFO_STR_CREDITS: strcpy(info->s, "Copyright Nicola Salmoria and the MAME Team"); break;
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DEFINE_LEGACY_SOUND_DEVICE(VOTRAX, votrax);
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//**************************************************************************
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//**************************************************************************
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#define TEMP_HACKS (1)
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#define LOG_TIMING (0)
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#define LOG_LOWPARAM (0)
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#define LOG_GLOTTAL (0)
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#define LOG_TRANSITION (0)
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//**************************************************************************
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//**************************************************************************
61
// note that according to the patent timing circuit, p1/p2 and phi1/phi2
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// run 4x faster than all references in the patent text
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const UINT32 P_CLOCK_BIT = 5; // 5 according to timing diagram
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const UINT32 PHI_CLOCK_BIT = 3; // 3 according to timing diagram
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//**************************************************************************
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//**************************************************************************
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// device type definition
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const device_type VOTRAX_SC01 = &device_creator<votrax_sc01_device>;
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// ROM definition for the Votrax phoneme ROM
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ROM_START( votrax_sc01 )
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ROM_REGION( 0x200, "phoneme", 0 )
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ROM_LOAD( "sc01.bin", 0x0000, 0x200, CRC(0353dd6c) SHA1(00e8e497b96a10bd9f4d7e559433c3c209b0d3a8) )
81
// textual phoneme names for debugging
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const char *const votrax_sc01_device::s_phoneme_table[64] =
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"EH3", "EH2", "EH1", "PA0", "DT", "A1", "A2", "ZH",
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"AH2", "I3", "I2", "I1", "M", "N", "B", "V",
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"CH", "SH", "Z", "AW1", "NG", "AH1", "OO1", "OO",
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"L", "K", "J", "H", "G", "F", "D", "S",
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"A", "AY", "Y1", "UH3", "AH", "P", "O", "I",
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"U", "Y", "T", "R", "E", "W", "AE", "AE1",
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"AW2", "UH2", "UH1", "UH", "O2", "O1", "IU", "U1",
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"THV", "TH", "ER", "EH", "E1", "AW", "PA1", "STOP"
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// this waveform is derived from measuring fig. 10 in the patent
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// it is only an approximation
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const double votrax_sc01_device::s_glottal_wave[16] =
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//**************************************************************************
120
//**************************************************************************
122
//-------------------------------------------------
123
// votrax_sc01_device - constructor
124
//-------------------------------------------------
126
votrax_sc01_device::votrax_sc01_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
127
: device_t(mconfig, VOTRAX_SC01, "Votrax SC-01", "votrax", tag, owner, clock),
128
device_sound_interface(mconfig, *this),
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m_phoneme_timer(NULL)
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//-------------------------------------------------
136
// static_set_interface - configuration helper
137
// to set the interface
138
//-------------------------------------------------
140
void votrax_sc01_device::static_set_interface(device_t &device, const votrax_sc01_interface &interface)
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votrax_sc01_device &votrax = downcast<votrax_sc01_device &>(device);
143
static_cast<votrax_sc01_interface &>(votrax) = interface;
148
//**************************************************************************
149
// READ/WRITE HANDLERS
150
//**************************************************************************
152
//-------------------------------------------------
153
// write - handle a write to the control register
154
//-------------------------------------------------
156
WRITE8_MEMBER( votrax_sc01_device::write )
158
// flush out anything currently processing
161
// only 6 bits matter
162
m_phoneme = data & 0x3f;
163
const UINT8 *rom = m_rom + (m_phoneme << 3);
164
mame_printf_debug("%s: STROBE %s (F1=%X F2=%X FC=%X F3=%X F2Q=%X VA=%X FA=%X CL=%X CLD=%X VD=%X PAC=%X PH=%02X)\n",
165
machine().time().as_string(3), s_phoneme_table[m_phoneme],
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rom[0] >> 4, rom[1] >> 4, rom[2] >> 4, rom[3] >> 4, rom[4] >> 4, rom[5] >> 4, rom[6] >> 4,
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rom[3] & 0xf, rom[4] & 0xf, rom[5] & 0xf, rom[6] & 0xf, rom[7]);
169
// the STROBE signal resets the phoneme counter
172
// not in the schematics, but necessary to fully reset the request latch
175
// clear the request signal
176
m_request_func(m_request_state = m_internal_request = CLEAR_LINE);
177
m_phoneme_timer->adjust(attotime::zero);
181
//-------------------------------------------------
182
// inflection_w - handle a write to the
184
//-------------------------------------------------
186
WRITE8_MEMBER( votrax_sc01_device::inflection_w )
188
// only 2 bits matter
190
if (m_inflection == data)
193
// append an inflection marker
200
//**************************************************************************
202
//**************************************************************************
204
//-------------------------------------------------
205
// update_subphoneme_clock_period - re-compute the
206
// period of the sub-phoneme clock, as a multiple
207
// of the master clock
208
//-------------------------------------------------
210
void votrax_sc01_device::update_subphoneme_clock_period()
212
assert(m_latch_80 < 128);
215
The sub-phoneme timing circuit is based off the switching capacitor
216
technique described in the Votrax patent. Replacing the capacitor
217
ladder with [Rx] representing the effective resistance, the circuit
218
becomes essentially a pair of op-amps:
224
+----------------------+
228
+--[Rx]--+----+-\ | | >
238
We have two op-amps, the left used as a standard amplifier, the right
239
one as a comparator. The circuit triggers when the two inputs of the
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right op-amp are equal.
242
The left part of the circuit (before C1) is simply a current injector.
243
It's all made of resistors, there's no modulated input, so everything
244
is going to be constant. If you don't know about op-amps used as
245
amplifiers, you just need to know that it forces its two inputs to
246
have the same voltage while not sending or providing any current
247
through there (only though its output in fact).
249
In the schema, the injected current is i2. Basic equations apply:
257
And the tipping happens when the voltage on the right of C1 reaches
261
(i2 being a constant, the integration is kinda easy)
264
R3.i3 = Rx.i2 -> i3 = Rx/R3.i2
266
Va + (Rx + R2 + R2.Rx/R3).i2 = Va + T/C1.i2
267
T = C1*(Rx*(1+R2/R3) + R2)
269
Which isn't, interestingly though not surprisingly, dependant on Vm,
270
R1 or R4. And you have to round it to the next multiple of
271
0.2ms+0.1ms due to the clocking on p2 and its offset to p1 (charging
272
only happens on p1 active), and add one p1/p2 cycle (0.2ms) for the
275
So now you have your base clock, which you have to multiply by 16 to
276
get the phoneme length.
284
// determine total capacitance
286
if ((m_latch_80 & 0x01) != 0) cx += 5e-12;
287
if ((m_latch_80 & 0x02) != 0) cx += 11e-12;
288
if ((m_latch_80 & 0x04) != 0) cx += 21e-12;
289
if ((m_latch_80 & 0x08) != 0) cx += 43e-12;
290
if ((m_latch_80 & 0x10) != 0) cx += 86e-12;
291
if ((m_latch_80 & 0x20) != 0) cx += 173e-12;
292
if ((m_latch_80 & 0x40) != 0) cx += 345e-12;
294
// apply the equation above to determine charging time
295
// note that the 5kHz listed above for P1 is for a nominal master
296
// clock frequency of 1.28MHz, meaning it is master clock / 128
297
// which should be the P1 clock but appears to be a bit different
298
double p1_frequency = double(m_master_clock_freq) / double(1 << (P_CLOCK_BIT + 2));
299
double rx = 1.0 / (p1_frequency * cx);
300
double period = 1000e-12 * (rx * (1.0 + 9e3 / 1e3) + 9e3);
302
// convert to master clock cycles and round up
303
m_subphoneme_period = UINT32(ceil(period * double(m_master_clock_freq)));
306
//-------------------------------------------------
307
// bits_to_caps - compute the final capacity from
308
// a grid of bit-selected caps
309
//-------------------------------------------------
311
double votrax_sc01_device::bits_to_caps(UINT32 value, int caps_count, const double *caps_values)
314
for(int i=0; i<caps_count; i++)
316
sum += caps_values[i];
321
Playing with analog filters, or where all the magic filter formulas are coming from.
323
First you start with an analog circuit, for instance this one:
327
| +--|C2|--+<V1 +--|C3|--+
329
| Vi +--[R1]--+ | |\ | | |\ |
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| -----+ +----+--+-\ | +--+-\ |
331
| +--|C1|--+ | >--+--[Rx]--+ | >--+----- Vo
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| | |/ +--[R0]--+ |/ |
336
| | | /-+--+--[R0]--+
337
| +--[R4]-------+--< |
341
You need to determine the transfer function H(s) of the circuit, which is
342
defined as the ratio Vo/Vi. To do that, you use some properties:
344
- The intensity through an element is equal to the voltage
345
difference through the element divided by the impedence
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- The impedence of a resistance is equal to its resistance
349
- The impedence of a capacitor is 1/(s*C) where C is its capacitance
351
- The impedence of elements in series is the sum of the impedences
353
- The impedence of elements in parallel is the inverse of the sum of
356
- The sum of all intensities flowing into a node is 0 (there's no
357
charge accumulation in a wire)
359
- An operational amplifier in looped mode is an interesting beast:
360
the intensity at its two inputs is always 0, and the voltage is
361
forced identical between the inputs. In our case, since the '+'
362
inputs are all tied to ground, that means that the '-' inputs are at
363
voltage 0, intensity 0.
365
From here we can build some equations. Noting:
370
Then computing the intensity flow at each '-' input we have:
371
Vi/X1 + V2/R4 + V1/X2 = 0
375
Wrangling the equations, one eventually gets:
377
| Vo/Vi = H(s) = (R4/R1) * -------------------------------------------
378
| 1 + s * C3*Rx*R4/R2 + s^2 * C2*C3*Rx*R4
380
To check the mathematics between the 's' stuff, check "Laplace
381
transform". In short, it's a nice way of manipulating derivatives
382
and integrals without having to manipulate derivatives and
385
With that transfer function, we first can compute what happens to
386
every frequency in the input signal. You just compute H(2i*pi*f)
387
where f is the frequency, which will give you a complex number
388
representing the amplitude and phase effect. To get the usual dB
389
curves, compute 20*log10(abs(v))).
391
Now, once you have an analog transfer function, you can build a
392
digital filter from it using what is called the bilinear transform.
394
In our case, we have an analog filter with the transfer function:
396
| H(s) = -------------------------
397
| 1 + k[1]*s + k[2]*s^2
399
We can always reintroduce the global multipler later, and it's 1 in
400
most of our cases anyway.
407
where zc = 2*pi*fr/tan(pi*fr/fs)
408
with fs = sampling frequency
409
and fr = most interesting frequency
411
Then we rewrite H in function of negative integer powers of z.
413
Noting m0 = zc*k[0], m1 = zc*k[1], m2=zc*zc*k[2],
415
a little equation wrangling then gives:
417
| (1+m0) + (3+m0) *z^-1 + (3-m0) *z^-2 + (1-m0)*z^-3
418
| H(z) = ----------------------------------------------------------------
419
| (1+m1+m2) + (3+m1-m2)*z^-1 + (3-m1-m2)*z^-2 + (1-m1+m2)*z^-3
421
That beast in the digital transfer function, of which you can
422
extract response curves by posing z = exp(2*i*pi*f/fs).
424
Note that the bilinear transform is an approximation, and H(z(f)) =
425
H(s(f)) only at frequency fr. And the shape of the filter will be
426
better respected around fr. If you look at the curves of the
427
filters we're interested in, the frequency:
428
fr = sqrt(abs(k[0]*k[1]-k[2]))/(2*pi*k[2])
430
which is a (good) approximation of the filter peak position is a
433
Note that terminology wise, the "standard" bilinear transform is
434
with fr = fs/2, and using a different fr is called "pre-warping".
436
So now we have a digital transfer function of the generic form:
438
| a[0] + a[1]*z^-1 + a[2]*z^-2 + a[3]*z^-3
439
| H(z) = --------------------------------------------
440
| b[0] + b[1]*z^-1 + b[2]*z^-2 + b[3]*z^-3
442
The magic then is that the powers of z represent time in samples.
443
Noting x the input stream and y the output stream, you have:
447
y*b[0]*z^0 + y*b[1]*z^-1 + y*b[2]*z^-2 + y*b[3]*z^-3 = x*a[0]*z^0 + x*a[1]*z^-1 + x*a[2]*z^-2 + x*a[3]*z^-3
451
y*z^0 = (x*a[0]*z^0 + x*a[1]*z^-1 + x*a[2]*z^-2 + x*a[3]*z^-3 - y*b[1]*z^-1 - y*b[2]*z^-2 - y*b[3]*z^-3) / b[0]
453
and powers of z being time in samples,
455
y[0] = (x[0]*a[0] + x[-1]*a[1] + x[-2]*a[2] + x[-3]*a[3] - y[-1]*b[1] - y[-2]*b[2] - y[-3]*b[3]) / b[0]
457
So you have a filter you can apply. Note that this is why you want
458
negative powers of z. Positive powers would mean looking into the
459
future (which is possible in some cases, in particular with x, and
460
has some very interesting properties, but is not very useful in
461
analog circuit simulation).
463
Note that if you have multiple inputs, all this stuff is linear.
464
Or, in other words, you just have to split it in multiple circuits
465
with only one input connected each time and sum the results. It
468
Also, since we're in practice in a dynamic system, for an amplifying
469
filter (i.e. where things like r4/r1 is not 1), it's better to
470
proceed in two steps:
472
- amplify the input by the current value of the coefficient, and
474
- apply the now non-amplifying filter to the historized amplified
477
That way reduces the probability of the output boucing all over the
483
//-------------------------------------------------------------
484
// filter_s_to_z - analog to digital filter transformation
485
//-------------------------------------------------------------
487
void votrax_sc01_device::filter_s_to_z(const double *k, double fs, double *a, double *b)
489
double fpeak = sqrt(fabs(k[0]*k[1]-k[2]))/(2*M_PI*k[2]);
490
double zc = 2*M_PI*fpeak/tan(M_PI*fpeak/fs);
494
double m2 = zc*zc*k[2];
507
//-------------------------------------------------------------
508
// apply_filter - apply the digital filter (before output
509
// shifting, so y[0] is one step in the past)
510
//-------------------------------------------------------------
511
double votrax_sc01_device::apply_filter(const double *x, const double *y, const double *a, const double *b)
513
return (x[0]*a[0] + x[1]*a[1] + x[2]*a[2] + x[3]*a[3] - y[0]*b[1] - y[1]*b[2] - y[2]*b[3]) / b[0];
517
//-------------------------------------------------------------
518
// shift_hist - shift a value in an output history
519
//-------------------------------------------------------------
521
void votrax_sc01_device::shift_hist(double val, double *hist_array, int hist_size)
523
for(int i = 0; i < hist_size-1; i++)
524
hist_array[hist_size-1-i] = hist_array[hist_size-2-i];
529
//-------------------------------------------------
530
// sound_stream_update - handle update requests
531
// for our sound stream
532
//-------------------------------------------------
534
void votrax_sc01_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
536
// determine how many master half-clocks per sample
537
int half_clocks_per_sample = (m_master_clock_freq * 2) / stream.sample_rate();
539
// iterate over clocks (samples)
540
stream_sample_t *dest = outputs[0];
543
// run the digital logic at the master clock rate
544
double glottal_out = 0;
545
UINT8 noise_out_digital = 0;
546
for (int curclock = 0; curclock < half_clocks_per_sample; curclock++)
548
if (LOG_TIMING | LOG_LOWPARAM | LOG_GLOTTAL | LOG_TRANSITION)
550
if (m_counter_34 % 32 == 0 && m_master_clock == 0)
553
mame_printf_debug("MCLK C034 L070 L072 BET1 P1 P2 PHI1 PHI2 PH1' PH2' SUBC C088 C084 L092 IIRQ ");
555
mame_printf_debug("F132 F114 F112 F142 L080 ");
557
mame_printf_debug("C220 C222 C224 C234 C236 FGAT GLSY ");
559
mame_printf_debug("0625 C046 L046 A0-2 L168 L170 FC VA FA F1 F2 F3 F2Q ");
560
mame_printf_debug("\n");
563
mame_printf_debug("%4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X ", m_master_clock, m_counter_34, m_latch_70, m_latch_72, m_beta1, m_p1, m_p2, m_phi1, m_phi2, m_phi1_20, m_phi2_20, m_subphoneme_count, m_clock_88, m_counter_84, m_latch_92, m_internal_request);
565
mame_printf_debug("%4X %4X %4X %4X %4X ", m_srff_132, m_srff_114, m_srff_112, m_srff_142, m_latch_80);
567
mame_printf_debug("%4X %4X %4X %4X %4X %4X %4X ", m_counter_220, m_counter_222, m_counter_224, m_counter_234, m_counter_236, m_fgate, m_glottal_sync);
569
mame_printf_debug("%4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X %4X ", m_0625_clock, m_counter_46, m_latch_46, m_latch_72 & 7, m_latch_168, m_latch_170, m_fc, m_va, m_fa, m_f1, m_f2, m_f3, m_f2q);
570
mame_printf_debug("\n");
573
//==============================================
575
// Timing circuit (patent figure 2a)
577
//==============================================
579
// update master clock
582
// on the falling edge of the master clock, advance the 10-bit counter at 34
583
UINT8 old_latch_72 = m_latch_72;
584
if (m_master_clock == 0)
585
m_counter_34 = (m_counter_34 + 1) & 0x3ff;
588
m_latch_70 = m_counter_34 & 0xf;
589
m_latch_72 = ((m_counter_34 >> 4) & 7) | ((m_counter_34 >> 6) & 8);
592
// derive beta 1 clock:
593
// set if m_latch_70.0 == 1
594
// reset if m_latch_70.0 == 0
595
// UINT8 old_beta1 = m_beta1;
596
m_beta1 = BIT(m_latch_70, 0);
599
// set if (m_counter_34.P_CLOCK_BIT & clock) == 1
600
// reset if (m_counter_34.P_CLOCK_BIT == 0)
602
if (BIT(m_counter_34, P_CLOCK_BIT) & m_master_clock)
604
else if (!BIT(m_counter_34, P_CLOCK_BIT))
608
// set if (!m_counter_34.P_CLOCK_BIT & clock) == 1
609
// reset if (m_counter_34.P_CLOCK_BIT == 1)
610
// UINT8 old_p1 = m_p1;
611
if (BIT(~m_counter_34, P_CLOCK_BIT) & m_master_clock)
613
else if (BIT(m_counter_34, P_CLOCK_BIT))
616
// derive phi2 clock:
617
// set if (m_counter_34.PHI_CLOCK_BIT & clock) == 1
618
// reset if (m_counter_34.PHI_CLOCK_BIT == 0)
619
UINT8 old_phi2 = m_phi2;
620
if (BIT(m_counter_34, PHI_CLOCK_BIT) & m_master_clock)
622
else if (!BIT(m_counter_34, PHI_CLOCK_BIT))
625
// derive phi1 clock:
626
// set if (!m_counter_34.PHI_CLOCK_BIT & clock) == 1
627
// reset if (m_counter_34.PHI_CLOCK_BIT == 1)
628
UINT8 old_phi1 = m_phi1;
629
if (BIT(~m_counter_34, PHI_CLOCK_BIT) & m_master_clock)
631
else if (BIT(m_counter_34, PHI_CLOCK_BIT))
634
// derive alternate phi2 clock:
635
// set if (m_counter_34.PHI_CLOCK_BIT & clock) == 1
636
// reset if (m_counter_34.PHI_CLOCK_BIT == 0)
637
UINT8 old_phi2_20 = m_phi2_20;
638
if (BIT(m_counter_34, PHI_CLOCK_BIT + 2) & m_master_clock)
640
else if (!BIT(m_counter_34, PHI_CLOCK_BIT + 2))
643
// derive alternate phi1 clock:
644
// set if (!m_counter_34.PHI_CLOCK_BIT & clock) == 1
645
// reset if (m_counter_34.PHI_CLOCK_BIT == 1)
646
// UINT8 old_phi1_20 = m_phi1_20;
647
if (BIT(~m_counter_34, PHI_CLOCK_BIT + 2) & m_master_clock)
649
else if (BIT(m_counter_34, PHI_CLOCK_BIT + 2))
652
// determine rising edges of each clock of interest
653
// UINT8 beta1_rising = (old_beta1 ^ m_beta1) & m_beta1;
654
UINT8 p2_rising = (old_p2 ^ m_p2) & m_p2;
655
// UINT8 p1_rising = (old_p1 ^ m_p1) & m_p1;
656
UINT8 phi2_rising = (old_phi2 ^ m_phi2) & m_phi2;
657
UINT8 phi1_rising = (old_phi1 ^ m_phi1) & m_phi1;
658
UINT8 phi2_20_rising = (old_phi2_20 ^ m_phi2_20) & m_phi2_20;
659
// UINT8 phi1_20_rising = (old_phi1_20 ^ m_phi1_20) & m_phi1_20;
660
UINT8 a0_rising = BIT((old_latch_72 ^ m_latch_72) & m_latch_72, 0);
661
UINT8 a2_rising = BIT((old_latch_72 ^ m_latch_72) & m_latch_72, 2);
662
UINT8 _125k_rising = BIT((old_latch_72 ^ m_latch_72) & m_latch_72, 3);
664
// track subphoneme counter state
665
if (!(m_latch_42 | m_phi1))
666
m_subphoneme_count = 0;
668
m_subphoneme_count++;
670
m_latch_42 = (m_subphoneme_count < m_subphoneme_period);
672
// update the state of the subphoneme clock line
673
UINT8 old_clock_88 = m_clock_88;
674
m_clock_88 = !m_latch_42; //!(m_latch_42 | m_phi1); -- figure 7 seems to be wrong here
675
UINT8 clock_88_rising = (old_clock_88 ^ m_clock_88) & m_clock_88;
677
// the A/R line holds the counter in reset except during phoneme processing,
678
// when it is clocked on the rising edge of the subphoneme timer clock
679
if (m_internal_request != CLEAR_LINE)
681
else if (clock_88_rising)
683
m_counter_84 = (m_counter_84 - 1) & 0x0f;
684
mame_printf_debug("counter=%d\n", m_counter_84);
687
// clock the zero count latch
689
m_latch_92 = ((m_counter_84 == 0) | (m_latch_92 << 1)) & 3;
691
// once both bits are set, the request line goes high
694
// if the request line was previously low, reset the VD/CLD flip-flops
695
if (m_internal_request == CLEAR_LINE)
696
m_srff_112 = m_srff_114 = 0;
697
m_internal_request = ASSERT_LINE;
700
//==============================================
702
// Low parameter clocking (patent figure 2b)
704
//==============================================
706
// fetch ROM data; note that the address lines come directly from
707
// counter_34 and not from the latches, which are 1 cycle delayed
708
UINT8 romdata = m_rom[(m_phoneme << 3) | ((m_counter_34 >> 4) & 7)];
710
// update the ROM data; ROM format is (upper nibble/lower nibble)
711
// +00 = F1 parameter / 0
712
// +01 = F2 parameter / 0
713
// +02 = FC parameter / 0
714
// +03 = F3 parameter / CL
715
// +04 = F2Q Parameter / CLD
716
// +05 = VA Parameter / VD
717
// +06 = FA Parameter / PAC
718
// +07 = Phoneme timing (full 7 bits)
720
// latch a new value from ROM on phi2
721
UINT8 a = m_latch_72 & 7;
722
UINT8 romdata_swapped;
729
m_srff_132 = m_srff_114 & BIT(~romdata, 3);
734
romdata_swapped = (BIT(romdata, 0) << 3) | (BIT(romdata, 1) << 2) | (BIT(romdata, 2) << 1) | (BIT(romdata, 3) << 0);
735
if (m_counter_84 != 0 && romdata_swapped == (m_counter_84 ^ 0xf))
741
romdata_swapped = (BIT(romdata, 0) << 3) | (BIT(romdata, 1) << 2) | (BIT(romdata, 2) << 1) | (BIT(romdata, 3) << 0);
742
if (m_counter_84 != 0 && romdata_swapped == (m_counter_84 ^ 0xf))
746
// update FF == PAC & (VA | FA)
748
m_srff_142 = BIT(romdata, 3);
753
if (m_latch_80 != (romdata & 0x7f))
755
m_latch_80 = romdata & 0x7f;
756
mame_printf_debug("[PH=%02X]\n", m_latch_80);
757
UINT32 old_period = m_subphoneme_period;
758
update_subphoneme_clock_period();
759
m_subphoneme_count = (m_subphoneme_count * m_subphoneme_period) / old_period;
760
m_phoneme_timer->adjust(attotime::zero);
766
//==============================================
768
// Glottal circuit (patent figure 6)
770
//==============================================
772
// determine the TC output from the counters (note that TC requires ET)
773
UINT8 counter_222_tc = (m_counter_222 == 0xf);
774
UINT8 counter_220_tc = (m_counter_220 == 0xf && counter_222_tc);
775
UINT8 counter_224_tc = (m_counter_224 == 0xf && counter_222_tc);
777
// clock glottal counter 224 on rising edge of a0
780
// counter 224 is only enabled if TC of counter 222 is 1
783
// if counter 220's TC is 1, do a load instead of a count
785
m_counter_224 = (m_inflection << 1) | ((~m_f1 & 0x8) >> 3);
787
m_counter_224 = (m_counter_224 + 1) & 0xf;
791
// clock remaining glottal counters (220, 222, 236) on rising edge of phi2
794
// counter 220 is only enabled if TC of counter 222 is 1
797
// if counter 220's TC is 1, do a load instead of a count
799
m_counter_220 = (m_inflection << 1) | ((~m_f1 & 0x8) >> 3);
801
m_counter_220 = (m_counter_220 + 1) & 0xf;
804
// counter 222 is always enabled
807
// if counter 220's TC is 1, do a load instead of a count
809
m_counter_222 = (~m_f1 & 0x7) << 1;
811
m_counter_222 = (m_counter_222 + 1) & 0xf;
814
// counter 236 is always enabled
817
m_counter_236 = (m_counter_236 + 1) & 0xf;
819
// rising edge of Q1 from counter 236 clocks counter 234
820
if ((m_counter_236 & 0x3) == 0x2)
822
// counter 234 is only enabled if it has not reached terminal
823
if (m_counter_234 != 0xf)
824
m_counter_234 = (m_counter_234 + 1) & 0xf;
829
// update FGATE state
835
// apply asynchronous clear to counters 234/236
836
if (counter_220_tc && m_phi1_20)
837
m_counter_236 = m_counter_234 = 0;
839
// derive glottal circuit output signals
841
UINT8 old_glottal_sync = m_glottal_sync;
843
m_glottal_sync = (m_counter_234 == 0);
844
glottal_out = s_glottal_wave[m_counter_234];
846
//==============================================
848
// Transition circuit (patent figure 3a/3b)
850
//==============================================
852
// divide 1.25k clock by 2 (lower-left of 46)
853
UINT8 old_0625_clock = m_0625_clock;
855
m_0625_clock = !m_0625_clock;
856
UINT8 _0625_rising = (old_0625_clock ^ m_0625_clock) & m_0625_clock;
858
// update counter above
861
if (m_counter_46 == 0xf)
864
m_counter_46 = (m_counter_46 + 1) & 0xf;
867
// and then the latch to the right
869
m_latch_46 = (BIT(m_counter_46, 1) << 0) |
870
(BIT(m_latch_46, 0) << 1) |
871
(m_0625_clock << 2) |
872
(BIT(m_latch_46, 2) << 3);
878
// determine the read/write signal
882
// write if not FF and low 2 bits of latch
883
// FF is the S/R flip-flop at 142 ANDed with !(/FA & /VA)
884
case 0: case 1: case 2: case 3: case 4:
885
if (!(m_srff_142 & !((m_fa == 0) & (m_va == 0))) && (m_latch_46 & 0x3) == 0x3)
890
if ((m_latch_46 & 0xc) == 0xc && m_srff_112)
895
if ((m_latch_46 & 0xc) == 0xc && m_srff_114)
900
// gate on the phi2 clock (OR gate @ 172)
903
// write the transitioned values to RAM if requested
904
// (note we consolidate the serial addition and clocking steps here)
907
UINT8 old = (m_latch_168 << 4) | m_latch_170;
908
m_ram[a] = old - (old >> 3) + ((romdata & 0xf0) >> 3);
911
// latch some parameter values on rising edge of phi2
930
// latch remaining parameter values on rising edge of (phi2 & glottal sync)
934
UINT8 old_phi2_glottal = (old_phi2 & old_glottal_sync);
935
UINT8 new_phi2_glottal = m_phi2 & m_glottal_sync;
936
if ((old_phi2_glottal ^ new_phi2_glottal) & new_phi2_glottal)
945
m_f2 = (m_latch_168 << 1) | (m_latch_170 >> 3);
957
// latch value from RAM on rising edge of phi1
960
m_latch_168 = m_ram[a] >> 4;
961
m_latch_170 = m_ram[a] & 0xf;
964
//==============================================
966
// Noise generator circuit (patent figure 8)
968
//==============================================
970
// nose is clocked by the NOR of /FA and P1
971
UINT8 old_noise_clock = m_noise_clock;
972
m_noise_clock = !((m_fa == 0) | m_p1);
973
UINT8 noise_clock_rising = (old_noise_clock ^ m_noise_clock) & m_noise_clock;
974
UINT8 noise_clock_falling = (old_noise_clock ^ m_noise_clock) & old_noise_clock;
976
// falling edge clocks the shift register
977
if (noise_clock_falling)
979
// shift register 252 is actually 4 shift registers (2 4-bit, 2 5-bit)
980
// d1 and d3 are the 4-bit registers, d2 and d4 are the 5-bit registers
981
// XOR'ed input goes into d4, which shifts in to d2, then d3, then d1
982
// thus the full 18-bit value is effectively
984
// d4 = (m_shift_252 >> 0) & 0x1f;
985
// d2 = (m_shift_252 >> 5) & 0x1f;
986
// d3 = (m_shift_252 >> 10) & 0xf;
987
// d1 = (m_shift_252 >> 14) & 0xf;
989
// input at the low end is ((d1+4 ^ d2+5) ^ (d4+4 ^ d4+5)) ^ !(counter2 | counter3)
990
// output is tapped at d3+4
992
UINT32 old_shift = m_shift_252;
994
m_shift_252 |= ((BIT(old_shift, 17) ^ BIT(old_shift, 9)) ^ (BIT(old_shift, 3) ^ BIT(old_shift, 4))) ^
995
((m_counter_250 & 0xc) == 0);
998
// rising edge clocks the counter
999
if (noise_clock_rising)
1001
// counter is reset to 1 if terminal, otherwise it increments
1002
if (m_counter_250 == 0xf)
1003
m_counter_250 = 0x1;
1005
m_counter_250 = (m_counter_250 + 1) & 0xf;
1008
// compute final noise out signal
1009
noise_out_digital = !(BIT(m_shift_252, 13) & (m_fgate | (m_va == 0)));
1012
// TODO: cache the filters
1014
double k[3], a[4], b[4];
1017
double fc = m_master_clock_freq / 30.0; // Nominal is 20KHz
1018
double fs = stream.sample_rate();
1020
// useful temporaries
1021
double rcp, rcq, rca;
1023
// amplification stage
1024
static const double va_caps[4] = { 27, 53, 107, 213 };
1025
double va_out = glottal_out * bits_to_caps(m_va, 4, va_caps) / 400;
1027
shift_hist(va_out, m_va_hist, 4);
1031
static const double fa_caps[4] = { 27, 53, 107, 213 };
1032
rcp = bits_to_caps(m_fa, 4, fa_caps);
1034
shift_hist(-noise_out_digital * 400*rcp/(358.0*100000*566*(fc*rcp*1e-12 + 1.0/100000 + 1.0/2000)), m_ni_hist, 4);
1036
k[0] = 400/(fc*358);
1037
k[1] = 400*400/(fc*358*566);
1038
k[2] = 400*400/(fc*fc*358*358);
1040
filter_s_to_z(k, fs, a, b);
1041
double no_out = apply_filter(m_ni_hist, m_no_hist, a, b);
1042
shift_hist(no_out, m_no_hist, 4);
1047
static const double s1_p_caps[4] = { 16.4, 33, 66, 130 };
1048
rcp = 24 + bits_to_caps(m_f1, 4, s1_p_caps);
1051
k[0] = 253/(fc*270);
1052
k[1] = 1080*rcq/(fc*270*rcp);
1053
k[2] = 1080*1080/(fc*fc*270*rcp);
1055
filter_s_to_z(k, fs, a, b);
1056
double s1_out = apply_filter(m_va_hist, m_s1_hist, a, b);
1057
shift_hist(s1_out, m_s1_hist, 4);
1060
// stage 2 filter, glottal half
1062
static const double s2_p_caps[5] = { 14, 28, 56, 113, 226 };
1063
static const double s2_q_caps[4] = { 23, 46, 93, 186 };
1064
rcp = 46 + bits_to_caps(m_f2, 5, s2_p_caps);
1065
rcq = 20 + bits_to_caps(m_f2q, 4, s2_q_caps);;
1067
k[0] = 400/(fc*470);
1068
k[1] = 620*rcq/(fc*470*rcp);
1069
k[2] = 620*620/(fc*fc*470*rcp);
1071
filter_s_to_z(k, fs, a, b);
1072
double s2g_out = apply_filter(m_s1_hist, m_s2g_hist, a, b);
1073
shift_hist(s2g_out, m_s2g_hist, 4);
1076
// stage 2 filter, noise half (rcp and rcq kept from stage 2 glottal)
1078
static const double s2_n_caps[5] = { 19, 38, 76, 152 };
1079
rca = bits_to_caps(m_fc, 4, s2_n_caps);
1081
shift_hist(-no_out*rcq*rca/(470*rcp), m_s2ni_hist, 4);
1083
k[0] = 400/(fc*470);
1084
k[1] = 620*rcq/(fc*470*rcp);
1085
k[2] = 620*620/(fc*fc*470*rcp);
1087
filter_s_to_z(k, fs, a, b);
1088
double s2n_out = apply_filter(m_s2ni_hist, m_s2n_hist, a, b);
1089
shift_hist(s2n_out, m_s2n_hist, 4);
1091
// sum the stage 2 outputs
1092
double s2_out = s2g_out + s2n_out;
1093
shift_hist(s2_out, m_s2_hist, 4);
1098
static const double s3_p_caps[4] = { 21, 42, 84, 168 };
1099
rcp = 76 + bits_to_caps(m_f3, 4, s3_p_caps);
1103
k[1] = 420*rcq/(fc*390*rcp);
1104
k[2] = 420*420/(fc*fc*390*rcp);
1106
filter_s_to_z(k, fs, a, b);
1107
double s3_out = apply_filter(m_s2_hist, m_s3_hist, a, b);
1108
shift_hist(s3_out, m_s3_hist, 4);
1111
// stage 4 filter, noise injection
1113
// The resulting non-amplifying filter is identical, so we
1114
// inject instead of splitting
1116
static const double s4_n_caps[4] = { 24, 48, 96, 192 };
1117
rca = 115 + bits_to_caps(~m_fc, 4, s4_n_caps);
1119
shift_hist(s3_out + no_out*470/rca, m_s4i_hist, 4);
1128
k[1] = 338*rcq/(fc*470*rcp);
1129
k[2] = 338*338/(fc*fc*470*rcp);
1131
filter_s_to_z(k, fs, a, b);
1132
double s4_out = apply_filter(m_s4i_hist, m_s4_hist, a, b);
1133
shift_hist(s4_out, m_s4_hist, 4);
1136
// TODO: apply closure circuit (undocumented)
1138
// output the current result
1139
*dest++ = INT16(s4_out * 4000);
1145
//**************************************************************************
1147
//**************************************************************************
1149
//-------------------------------------------------
1150
// rom_region - return a pointer to the device's
1151
// internal ROM region
1152
//-------------------------------------------------
1154
const rom_entry *votrax_sc01_device::device_rom_region() const
1156
return ROM_NAME( votrax_sc01 );
1160
//-------------------------------------------------
1161
// device_start - handle device startup
1162
//-------------------------------------------------
1164
void votrax_sc01_device::device_start()
1166
// initialize internal state
1167
m_master_clock_freq = clock();
1168
m_stream = stream_alloc(0, 1, m_master_clock_freq / 16);
1169
m_phoneme_timer = timer_alloc();
1170
m_rom = memregion("phoneme")->base();
1177
m_request_func.resolve(m_request_cb, *this);
1178
m_request_state = ASSERT_LINE;
1179
m_internal_request = ASSERT_LINE;
1182
save_item(NAME(m_inflection));
1183
save_item(NAME(m_phoneme));
1186
save_item(NAME(m_request_state));
1187
save_item(NAME(m_internal_request));
1189
// save timing circuit
1190
save_item(NAME(m_master_clock_freq));
1191
save_item(NAME(m_master_clock));
1192
save_item(NAME(m_counter_34));
1193
save_item(NAME(m_latch_70));
1194
save_item(NAME(m_latch_72));
1195
save_item(NAME(m_beta1));
1196
save_item(NAME(m_p2));
1197
save_item(NAME(m_p1));
1198
save_item(NAME(m_phi2));
1199
save_item(NAME(m_phi1));
1200
save_item(NAME(m_subphoneme_period));
1201
save_item(NAME(m_subphoneme_count));
1202
save_item(NAME(m_clock_88));
1203
save_item(NAME(m_latch_42));
1204
save_item(NAME(m_counter_84));
1205
save_item(NAME(m_latch_92));
1207
// save low parameter clocking
1208
save_item(NAME(m_srff_132));
1209
save_item(NAME(m_srff_114));
1210
save_item(NAME(m_srff_112));
1211
save_item(NAME(m_srff_142));
1212
save_item(NAME(m_latch_80));
1214
// save glottal circuit
1215
save_item(NAME(m_counter_220));
1216
save_item(NAME(m_counter_222));
1217
save_item(NAME(m_counter_224));
1218
save_item(NAME(m_counter_234));
1219
save_item(NAME(m_counter_236));
1220
save_item(NAME(m_fgate));
1221
save_item(NAME(m_glottal_sync));
1223
// save transition circuit
1224
save_item(NAME(m_0625_clock));
1225
save_item(NAME(m_counter_46));
1226
save_item(NAME(m_latch_46));
1227
save_item(NAME(m_ram));
1228
save_item(NAME(m_latch_168));
1229
save_item(NAME(m_latch_170));
1230
save_item(NAME(m_f1));
1231
save_item(NAME(m_f2));
1232
save_item(NAME(m_fc));
1233
save_item(NAME(m_f3));
1234
save_item(NAME(m_f2q));
1235
save_item(NAME(m_va));
1236
save_item(NAME(m_fa));
1238
// save noise generator circuit
1239
save_item(NAME(m_noise_clock));
1240
save_item(NAME(m_shift_252));
1241
save_item(NAME(m_counter_250));
1243
// save filter histories
1244
save_item(NAME(m_ni_hist));
1245
save_item(NAME(m_no_hist));
1246
save_item(NAME(m_va_hist));
1247
save_item(NAME(m_s1_hist));
1248
save_item(NAME(m_s2g_hist));
1249
save_item(NAME(m_s2n_hist));
1250
save_item(NAME(m_s2ni_hist));
1251
save_item(NAME(m_s2_hist));
1252
save_item(NAME(m_s3_hist));
1253
save_item(NAME(m_s4i_hist));
1254
save_item(NAME(m_s4_hist));
1258
//-------------------------------------------------
1259
// device_reset - handle device reset
1260
//-------------------------------------------------
1262
void votrax_sc01_device::device_reset()
1264
// set the initial state
1269
m_request_func(m_internal_request = m_request_state = ASSERT_LINE);
1271
// reset timing circuit
1281
m_subphoneme_period = 1000;
1282
m_subphoneme_count = 0;
1288
// reset low parameter clocking
1294
update_subphoneme_clock_period();
1296
// reset glottal circuit
1305
// reset transition circuit
1309
memset(m_ram, 0, sizeof(m_ram));
1320
// reset noise circuit
1325
// reset filter histories
1326
memset(m_ni_hist, 0, sizeof(m_ni_hist));
1327
memset(m_no_hist, 0, sizeof(m_no_hist));
1328
memset(m_va_hist, 0, sizeof(m_va_hist));
1329
memset(m_s1_hist, 0, sizeof(m_s1_hist));
1330
memset(m_s2g_hist, 0, sizeof(m_s2g_hist));
1331
memset(m_s2n_hist, 0, sizeof(m_s2n_hist));
1332
memset(m_s2ni_hist, 0, sizeof(m_s2ni_hist));
1333
memset(m_s2_hist, 0, sizeof(m_s2_hist));
1334
memset(m_s3_hist, 0, sizeof(m_s3_hist));
1335
memset(m_s4i_hist, 0, sizeof(m_s4i_hist));
1336
memset(m_s4_hist, 0, sizeof(m_s4_hist));
1340
//-------------------------------------------------
1341
// device_clock_changed - handle dynamic clock
1342
// changes by altering our output frequency
1343
//-------------------------------------------------
1345
void votrax_sc01_device::device_clock_changed()
1347
// compute new frequency of the master clock, and update if changed
1348
UINT32 newfreq = clock();
1349
if (newfreq != m_master_clock_freq)
1351
// if we have a stream
1352
if (m_stream != NULL)
1355
m_stream->set_sample_rate(newfreq / 16);
1358
// determine how many clock ticks remained on the phoneme timer
1359
UINT64 remaining = m_phoneme_timer->remaining().as_ticks(m_master_clock_freq);
1361
// recompute the master clock
1362
m_master_clock_freq = newfreq;
1364
// adjust the phoneme timer to the same number of ticks based on the new frequency
1366
m_phoneme_timer->adjust(attotime::from_ticks(remaining, newfreq));
1371
//-------------------------------------------------
1372
// device_timer - handle device timer
1373
//-------------------------------------------------
1375
void votrax_sc01_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
1377
// force a stream update
1380
// if we're requesting more data, no need for timing
1381
if (m_request_state == ASSERT_LINE)
1384
// if we're supposed to have fired, do it now
1385
if (m_internal_request == ASSERT_LINE)
1387
mame_printf_debug("%s: REQUEST\n", timer.machine().time().as_string(3));
1388
m_request_func(m_request_state = ASSERT_LINE);
1392
// account for the rest of this subphoneme clock
1393
UINT32 clocks_until_request = 0;
1394
if (m_counter_84 != 0)
1396
if (m_subphoneme_count < m_subphoneme_period)
1397
clocks_until_request += m_subphoneme_period - m_subphoneme_count;
1398
clocks_until_request += m_subphoneme_period * (m_counter_84 - 1);
1402
clocks_until_request = MAX(clocks_until_request, (1 << P_CLOCK_BIT) / 2);
1403
timer.adjust(attotime::from_ticks(clocks_until_request, m_master_clock_freq));
added
removed
src/emu/sound/votrax.c
