/************************************************************************************** * Game Boy sound emulation (c) Anthony Kruize (trandor@labyrinth.net.au) * * Anyways, sound on the Game Boy consists of 4 separate 'channels' * Sound1 = Quadrangular waves with SWEEP and ENVELOPE functions (NR10,11,12,13,14) * Sound2 = Quadrangular waves with ENVELOPE functions (NR21,22,23,24) * Sound3 = Wave patterns from WaveRAM (NR30,31,32,33,34) * Sound4 = White noise with an envelope (NR41,42,43,44) * * Each sound channel has 2 modes, namely ON and OFF... whoa * * These tend to be the two most important equations in * converting between Hertz and GB frequency registers: * (Sounds will have a 2.4% higher frequency on Super GB.) * gb = 2048 - (131072 / Hz) * Hz = 131072 / (2048 - gb) * * Changes: * * 10/2/2002 AK - Preliminary sound code. * 13/2/2002 AK - Added a hack for mode 4, other fixes. * 23/2/2002 AK - Use lookup tables, added sweep to mode 1. Re-wrote the square * wave generation. * 13/3/2002 AK - Added mode 3, better lookup tables, other adjustments. * 15/3/2002 AK - Mode 4 can now change frequencies. * 31/3/2002 AK - Accidently forgot to handle counter/consecutive for mode 1. * 3/4/2002 AK - Mode 1 sweep can still occur if shift is 0. Don't let frequency * go past the maximum allowed value. Fixed Mode 3 length table. * Slight adjustment to Mode 4's period table generation. * 5/4/2002 AK - Mode 4 is done correctly, using a polynomial counter instead * of being a total hack. * 6/4/2002 AK - Slight tweak to mode 3's frequency calculation. * 13/4/2002 AK - Reset envelope value when sound is initialized. * 21/4/2002 AK - Backed out the mode 3 frequency calculation change. * Merged init functions into gameboy_sound_w(). * 14/5/2002 AK - Removed magic numbers in the fixed point math. * 12/6/2002 AK - Merged SOUNDx structs into one SOUND struct. * 26/10/2002 AK - Finally fixed channel 3! * ***************************************************************************************/ #include "emu.h" #include "gb.h" /*************************************************************************** CONSTANTS ***************************************************************************/ #define NR10 0x00 #define NR11 0x01 #define NR12 0x02 #define NR13 0x03 #define NR14 0x04 #define NR21 0x06 #define NR22 0x07 #define NR23 0x08 #define NR24 0x09 #define NR30 0x0A #define NR31 0x0B #define NR32 0x0C #define NR33 0x0D #define NR34 0x0E #define NR41 0x10 #define NR42 0x11 #define NR43 0x12 #define NR44 0x13 #define NR50 0x14 #define NR51 0x15 #define NR52 0x16 #define AUD3W0 0x20 #define AUD3W1 0x21 #define AUD3W2 0x22 #define AUD3W3 0x23 #define AUD3W4 0x24 #define AUD3W5 0x25 #define AUD3W6 0x26 #define AUD3W7 0x27 #define AUD3W8 0x28 #define AUD3W9 0x29 #define AUD3WA 0x2A #define AUD3WB 0x2B #define AUD3WC 0x2C #define AUD3WD 0x2D #define AUD3WE 0x2E #define AUD3WF 0x2F #define LEFT 1 #define RIGHT 2 #define MAX_FREQUENCIES 2048 #define FIXED_POINT 16 /* Represents wave duties of 12.5%, 25%, 50% and 75% */ static const float wave_duty_table[4] = { 8.0f, 4.0f, 2.0f, 1.33f }; /*************************************************************************** TYPE DEFINITIONS ***************************************************************************/ struct SOUND { /* Common */ UINT8 on; UINT8 channel; INT32 length; INT32 pos; UINT32 period; INT32 count; INT8 mode; /* Mode 1, 2, 3 */ INT8 duty; /* Mode 1, 2, 4 */ INT32 env_value; INT8 env_direction; INT32 env_length; INT32 env_count; INT8 signal; /* Mode 1 */ UINT32 frequency; INT32 swp_shift; INT32 swp_direction; INT32 swp_time; INT32 swp_count; /* Mode 3 */ INT8 level; UINT8 offset; UINT32 dutycount; /* Mode 4 */ INT32 ply_step; INT16 ply_value; }; struct SOUNDC { UINT8 on; UINT8 vol_left; UINT8 vol_right; UINT8 mode1_left; UINT8 mode1_right; UINT8 mode2_left; UINT8 mode2_right; UINT8 mode3_left; UINT8 mode3_right; UINT8 mode4_left; UINT8 mode4_right; }; struct gb_sound_t { sound_stream *channel; int rate; INT32 env_length_table[8]; INT32 swp_time_table[8]; UINT32 period_table[MAX_FREQUENCIES]; UINT32 period_mode3_table[MAX_FREQUENCIES]; UINT32 period_mode4_table[8][16]; UINT32 length_table[64]; UINT32 length_mode3_table[256]; struct SOUND snd_1; struct SOUND snd_2; struct SOUND snd_3; struct SOUND snd_4; struct SOUNDC snd_control; UINT8 snd_regs[0x30]; }; /*************************************************************************** INLINE FUNCTIONS ***************************************************************************/ INLINE gb_sound_t *get_token(device_t *device) { assert(device != NULL); assert(device->type() == GAMEBOY); return (gb_sound_t *) downcast(device)->token(); } /*************************************************************************** PROTOTYPES ***************************************************************************/ static STREAM_UPDATE( gameboy_update ); /*************************************************************************** IMPLEMENTATION ***************************************************************************/ READ8_DEVICE_HANDLER( gb_wave_r ) { gb_sound_t *gb = get_token(device); /* TODO: properly emulate scrambling of wave ram area when playback is active */ return ( gb->snd_regs[ AUD3W0 + offset ] | gb->snd_3.on ); } WRITE8_DEVICE_HANDLER( gb_wave_w ) { gb_sound_t *gb = get_token(device); gb->snd_regs[ AUD3W0 + offset ] = data; } READ8_DEVICE_HANDLER( gb_sound_r ) { gb_sound_t *gb = get_token(device); switch( offset ) { case 0x05: case 0x0F: return 0xFF; case NR52: return 0x70 | gb->snd_regs[offset]; default: return gb->snd_regs[offset]; } } static void gb_sound_w_internal(device_t *device, int offset, UINT8 data ) { gb_sound_t *gb = get_token(device); /* Store the value */ gb->snd_regs[offset] = data; switch( offset ) { /*MODE 1 */ case NR10: /* Sweep (R/W) */ gb->snd_1.swp_shift = data & 0x7; gb->snd_1.swp_direction = (data & 0x8) >> 3; gb->snd_1.swp_direction |= gb->snd_1.swp_direction - 1; gb->snd_1.swp_time = gb->swp_time_table[ (data & 0x70) >> 4 ]; break; case NR11: /* Sound length/Wave pattern duty (R/W) */ gb->snd_1.duty = (data & 0xC0) >> 6; gb->snd_1.length = gb->length_table[data & 0x3F]; break; case NR12: /* Envelope (R/W) */ gb->snd_1.env_value = data >> 4; gb->snd_1.env_direction = (data & 0x8) >> 3; gb->snd_1.env_direction |= gb->snd_1.env_direction - 1; gb->snd_1.env_length = gb->env_length_table[data & 0x7]; break; case NR13: /* Frequency lo (R/W) */ gb->snd_1.frequency = ((gb->snd_regs[NR14]&0x7)<<8) | gb->snd_regs[NR13]; gb->snd_1.period = gb->period_table[gb->snd_1.frequency]; break; case NR14: /* Frequency hi / Initialize (R/W) */ gb->snd_1.mode = (data & 0x40) >> 6; gb->snd_1.frequency = ((gb->snd_regs[NR14]&0x7)<<8) | gb->snd_regs[NR13]; gb->snd_1.period = gb->period_table[gb->snd_1.frequency]; if( data & 0x80 ) { if( !gb->snd_1.on ) gb->snd_1.pos = 0; gb->snd_1.on = 1; gb->snd_1.count = 0; gb->snd_1.env_value = gb->snd_regs[NR12] >> 4; gb->snd_1.env_count = 0; gb->snd_1.swp_count = 0; gb->snd_1.signal = 0x1; gb->snd_regs[NR52] |= 0x1; } break; /*MODE 2 */ case NR21: /* Sound length/Wave pattern duty (R/W) */ gb->snd_2.duty = (data & 0xC0) >> 6; gb->snd_2.length = gb->length_table[data & 0x3F]; break; case NR22: /* Envelope (R/W) */ gb->snd_2.env_value = data >> 4; gb->snd_2.env_direction = (data & 0x8 ) >> 3; gb->snd_2.env_direction |= gb->snd_2.env_direction - 1; gb->snd_2.env_length = gb->env_length_table[data & 0x7]; break; case NR23: /* Frequency lo (R/W) */ gb->snd_2.period = gb->period_table[((gb->snd_regs[NR24]&0x7)<<8) | gb->snd_regs[NR23]]; break; case NR24: /* Frequency hi / Initialize (R/W) */ gb->snd_2.mode = (data & 0x40) >> 6; gb->snd_2.period = gb->period_table[((gb->snd_regs[NR24]&0x7)<<8) | gb->snd_regs[NR23]]; if( data & 0x80 ) { if( !gb->snd_2.on ) gb->snd_2.pos = 0; gb->snd_2.on = 1; gb->snd_2.count = 0; gb->snd_2.env_value = gb->snd_regs[NR22] >> 4; gb->snd_2.env_count = 0; gb->snd_2.signal = 0x1; gb->snd_regs[NR52] |= 0x2; } break; /*MODE 3 */ case NR30: /* Sound On/Off (R/W) */ gb->snd_3.on = (data & 0x80) >> 7; break; case NR31: /* Sound Length (R/W) */ gb->snd_3.length = gb->length_mode3_table[data]; break; case NR32: /* Select Output Level */ gb->snd_3.level = (data & 0x60) >> 5; break; case NR33: /* Frequency lo (W) */ gb->snd_3.period = gb->period_mode3_table[((gb->snd_regs[NR34]&0x7)<<8) + gb->snd_regs[NR33]]; break; case NR34: /* Frequency hi / Initialize (W) */ gb->snd_3.mode = (data & 0x40) >> 6; gb->snd_3.period = gb->period_mode3_table[((gb->snd_regs[NR34]&0x7)<<8) + gb->snd_regs[NR33]]; if( data & 0x80 ) { if( !gb->snd_3.on ) { gb->snd_3.pos = 0; gb->snd_3.offset = 0; gb->snd_3.duty = 0; } gb->snd_3.on = 1; gb->snd_3.count = 0; gb->snd_3.duty = 1; gb->snd_3.dutycount = 0; gb->snd_regs[NR52] |= 0x4; } break; /*MODE 4 */ case NR41: /* Sound Length (R/W) */ gb->snd_4.length = gb->length_table[data & 0x3F]; break; case NR42: /* Envelope (R/W) */ gb->snd_4.env_value = data >> 4; gb->snd_4.env_direction = (data & 0x8 ) >> 3; gb->snd_4.env_direction |= gb->snd_4.env_direction - 1; gb->snd_4.env_length = gb->env_length_table[data & 0x7]; break; case NR43: /* Polynomial Counter/Frequency */ gb->snd_4.period = gb->period_mode4_table[data & 0x7][(data & 0xF0) >> 4]; gb->snd_4.ply_step = (data & 0x8) >> 3; break; case NR44: /* Counter/Consecutive / Initialize (R/W) */ gb->snd_4.mode = (data & 0x40) >> 6; if( data & 0x80 ) { if( !gb->snd_4.on ) gb->snd_4.pos = 0; gb->snd_4.on = 1; gb->snd_4.count = 0; gb->snd_4.env_value = gb->snd_regs[NR42] >> 4; gb->snd_4.env_count = 0; gb->snd_4.signal = device->machine().rand(); gb->snd_4.ply_value = 0x7fff; gb->snd_regs[NR52] |= 0x8; } break; /* CONTROL */ case NR50: /* Channel Control / On/Off / Volume (R/W) */ gb->snd_control.vol_left = data & 0x7; gb->snd_control.vol_right = (data & 0x70) >> 4; break; case NR51: /* Selection of Sound Output Terminal */ gb->snd_control.mode1_right = data & 0x1; gb->snd_control.mode1_left = (data & 0x10) >> 4; gb->snd_control.mode2_right = (data & 0x2) >> 1; gb->snd_control.mode2_left = (data & 0x20) >> 5; gb->snd_control.mode3_right = (data & 0x4) >> 2; gb->snd_control.mode3_left = (data & 0x40) >> 6; gb->snd_control.mode4_right = (data & 0x8) >> 3; gb->snd_control.mode4_left = (data & 0x80) >> 7; break; case NR52: /* Sound On/Off (R/W) */ /* Only bit 7 is writable, writing to bits 0-3 does NOT enable or disable sound. They are read-only */ gb->snd_control.on = (data & 0x80) >> 7; if( !gb->snd_control.on ) { gb_sound_w_internal( device, NR10, 0x80 ); gb_sound_w_internal( device, NR11, 0x3F ); gb_sound_w_internal( device, NR12, 0x00 ); gb_sound_w_internal( device, NR13, 0xFE ); gb_sound_w_internal( device, NR14, 0xBF ); // gb_sound_w_internal( device, NR20, 0xFF ); gb_sound_w_internal( device, NR21, 0x3F ); gb_sound_w_internal( device, NR22, 0x00 ); gb_sound_w_internal( device, NR23, 0xFF ); gb_sound_w_internal( device, NR24, 0xBF ); gb_sound_w_internal( device, NR30, 0x7F ); gb_sound_w_internal( device, NR31, 0xFF ); gb_sound_w_internal( device, NR32, 0x9F ); gb_sound_w_internal( device, NR33, 0xFF ); gb_sound_w_internal( device, NR34, 0xBF ); // gb_sound_w_internal( device, NR40, 0xFF ); gb_sound_w_internal( device, NR41, 0xFF ); gb_sound_w_internal( device, NR42, 0x00 ); gb_sound_w_internal( device, NR43, 0x00 ); gb_sound_w_internal( device, NR44, 0xBF ); gb_sound_w_internal( device, NR50, 0x00 ); gb_sound_w_internal( device, NR51, 0x00 ); gb->snd_1.on = 0; gb->snd_2.on = 0; gb->snd_3.on = 0; gb->snd_4.on = 0; gb->snd_regs[offset] = 0; } break; } } WRITE8_DEVICE_HANDLER( gb_sound_w ) { gb_sound_t *gb = get_token(device); /* change in registers so update first */ gb->channel->update(); /* Only register NR52 is accessible if the sound controller is disabled */ if( !gb->snd_control.on && offset != NR52 ) { return; } gb_sound_w_internal( device, offset, data ); } static STREAM_UPDATE( gameboy_update ) { gb_sound_t *gb = get_token(device); stream_sample_t sample, left, right, mode4_mask; while( samples-- > 0 ) { left = right = 0; /* Mode 1 - Wave with Envelope and Sweep */ if( gb->snd_1.on ) { sample = gb->snd_1.signal * gb->snd_1.env_value; gb->snd_1.pos++; if( gb->snd_1.pos == (UINT32)(gb->snd_1.period / wave_duty_table[gb->snd_1.duty]) >> FIXED_POINT) { gb->snd_1.signal = -gb->snd_1.signal; } else if( gb->snd_1.pos > (gb->snd_1.period >> FIXED_POINT) ) { gb->snd_1.pos = 0; gb->snd_1.signal = -gb->snd_1.signal; } if( gb->snd_1.length && gb->snd_1.mode ) { gb->snd_1.count++; if( gb->snd_1.count >= gb->snd_1.length ) { gb->snd_1.on = 0; gb->snd_regs[NR52] &= 0xFE; } } if( gb->snd_1.env_length ) { gb->snd_1.env_count++; if( gb->snd_1.env_count >= gb->snd_1.env_length ) { gb->snd_1.env_count = 0; gb->snd_1.env_value += gb->snd_1.env_direction; if( gb->snd_1.env_value < 0 ) gb->snd_1.env_value = 0; if( gb->snd_1.env_value > 15 ) gb->snd_1.env_value = 15; } } if( gb->snd_1.swp_time ) { gb->snd_1.swp_count++; if( gb->snd_1.swp_count >= gb->snd_1.swp_time ) { gb->snd_1.swp_count = 0; if( gb->snd_1.swp_direction > 0 ) { gb->snd_1.frequency -= gb->snd_1.frequency / (1 << gb->snd_1.swp_shift ); if( gb->snd_1.frequency <= 0 ) { gb->snd_1.on = 0; gb->snd_regs[NR52] &= 0xFE; } } else { gb->snd_1.frequency += gb->snd_1.frequency / (1 << gb->snd_1.swp_shift ); if( gb->snd_1.frequency >= MAX_FREQUENCIES ) { gb->snd_1.frequency = MAX_FREQUENCIES - 1; } } gb->snd_1.period = gb->period_table[gb->snd_1.frequency]; } } if( gb->snd_control.mode1_left ) left += sample; if( gb->snd_control.mode1_right ) right += sample; } /* Mode 2 - Wave with Envelope */ if( gb->snd_2.on ) { sample = gb->snd_2.signal * gb->snd_2.env_value; gb->snd_2.pos++; if( gb->snd_2.pos == (UINT32)(gb->snd_2.period / wave_duty_table[gb->snd_2.duty]) >> FIXED_POINT) { gb->snd_2.signal = -gb->snd_2.signal; } else if( gb->snd_2.pos > (gb->snd_2.period >> FIXED_POINT) ) { gb->snd_2.pos = 0; gb->snd_2.signal = -gb->snd_2.signal; } if( gb->snd_2.length && gb->snd_2.mode ) { gb->snd_2.count++; if( gb->snd_2.count >= gb->snd_2.length ) { gb->snd_2.on = 0; gb->snd_regs[NR52] &= 0xFD; } } if( gb->snd_2.env_length ) { gb->snd_2.env_count++; if( gb->snd_2.env_count >= gb->snd_2.env_length ) { gb->snd_2.env_count = 0; gb->snd_2.env_value += gb->snd_2.env_direction; if( gb->snd_2.env_value < 0 ) gb->snd_2.env_value = 0; if( gb->snd_2.env_value > 15 ) gb->snd_2.env_value = 15; } } if( gb->snd_control.mode2_left ) left += sample; if( gb->snd_control.mode2_right ) right += sample; } /* Mode 3 - Wave patterns from WaveRAM */ if( gb->snd_3.on ) { /* NOTE: This is extremely close, but not quite right. The problem is for GB frequencies above 2000 the frequency gets clipped. This is caused because gb->snd_3.pos is never 0 at the test.*/ sample = gb->snd_regs[AUD3W0 + (gb->snd_3.offset/2)]; if( !(gb->snd_3.offset % 2) ) { sample >>= 4; } sample = (sample & 0xF) - 8; if( gb->snd_3.level ) sample >>= (gb->snd_3.level - 1); else sample = 0; gb->snd_3.pos++; if( gb->snd_3.pos >= ((UINT32)(((gb->snd_3.period ) >> 21)) + gb->snd_3.duty) ) { gb->snd_3.pos = 0; if( gb->snd_3.dutycount == ((UINT32)(((gb->snd_3.period ) >> FIXED_POINT)) % 32) ) { gb->snd_3.duty--; } gb->snd_3.dutycount++; gb->snd_3.offset++; if( gb->snd_3.offset > 31 ) { gb->snd_3.offset = 0; gb->snd_3.duty = 1; gb->snd_3.dutycount = 0; } } if( gb->snd_3.length && gb->snd_3.mode ) { gb->snd_3.count++; if( gb->snd_3.count >= gb->snd_3.length ) { gb->snd_3.on = 0; gb->snd_regs[NR52] &= 0xFB; } } if( gb->snd_control.mode3_left ) left += sample; if( gb->snd_control.mode3_right ) right += sample; } /* Mode 4 - Noise with Envelope */ if( gb->snd_4.on ) { /* Similar problem to Mode 3, we seem to miss some notes */ sample = gb->snd_4.signal & gb->snd_4.env_value; gb->snd_4.pos++; if( gb->snd_4.pos == (gb->snd_4.period >> (FIXED_POINT + 1)) ) { /* Using a Polynomial Counter (aka Linear Feedback Shift Register) Mode 4 has a 7 bit and 15 bit counter so we need to shift the bits around accordingly */ mode4_mask = (((gb->snd_4.ply_value & 0x2) >> 1) ^ (gb->snd_4.ply_value & 0x1)) << (gb->snd_4.ply_step ? 6 : 14); gb->snd_4.ply_value >>= 1; gb->snd_4.ply_value |= mode4_mask; gb->snd_4.ply_value &= (gb->snd_4.ply_step ? 0x7f : 0x7fff); gb->snd_4.signal = (INT8)gb->snd_4.ply_value; } else if( gb->snd_4.pos > (gb->snd_4.period >> FIXED_POINT) ) { gb->snd_4.pos = 0; mode4_mask = (((gb->snd_4.ply_value & 0x2) >> 1) ^ (gb->snd_4.ply_value & 0x1)) << (gb->snd_4.ply_step ? 6 : 14); gb->snd_4.ply_value >>= 1; gb->snd_4.ply_value |= mode4_mask; gb->snd_4.ply_value &= (gb->snd_4.ply_step ? 0x7f : 0x7fff); gb->snd_4.signal = (INT8)gb->snd_4.ply_value; } if( gb->snd_4.length && gb->snd_4.mode ) { gb->snd_4.count++; if( gb->snd_4.count >= gb->snd_4.length ) { gb->snd_4.on = 0; gb->snd_regs[NR52] &= 0xF7; } } if( gb->snd_4.env_length ) { gb->snd_4.env_count++; if( gb->snd_4.env_count >= gb->snd_4.env_length ) { gb->snd_4.env_count = 0; gb->snd_4.env_value += gb->snd_4.env_direction; if( gb->snd_4.env_value < 0 ) gb->snd_4.env_value = 0; if( gb->snd_4.env_value > 15 ) gb->snd_4.env_value = 15; } } if( gb->snd_control.mode4_left ) left += sample; if( gb->snd_control.mode4_right ) right += sample; } /* Adjust for master volume */ left *= gb->snd_control.vol_left; right *= gb->snd_control.vol_right; /* pump up the volume */ left <<= 6; right <<= 6; /* Update the buffers */ *(outputs[0]++) = left; *(outputs[1]++) = right; } gb->snd_regs[NR52] = (gb->snd_regs[NR52]&0xf0) | gb->snd_1.on | (gb->snd_2.on << 1) | (gb->snd_3.on << 2) | (gb->snd_4.on << 3); } static DEVICE_START( gameboy_sound ) { gb_sound_t *gb = get_token(device); int I, J; memset(&gb->snd_1, 0, sizeof(gb->snd_1)); memset(&gb->snd_2, 0, sizeof(gb->snd_2)); memset(&gb->snd_3, 0, sizeof(gb->snd_3)); memset(&gb->snd_4, 0, sizeof(gb->snd_4)); gb->channel = device->machine().sound().stream_alloc(*device, 0, 2, device->machine().sample_rate(), 0, gameboy_update); gb->rate = device->machine().sample_rate(); /* Calculate the envelope and sweep tables */ for( I = 0; I < 8; I++ ) { gb->env_length_table[I] = (I * ((1 << FIXED_POINT) / 64) * gb->rate) >> FIXED_POINT; gb->swp_time_table[I] = (((I << FIXED_POINT) / 128) * gb->rate) >> (FIXED_POINT - 1); } /* Calculate the period tables */ for( I = 0; I < MAX_FREQUENCIES; I++ ) { gb->period_table[I] = ((1 << FIXED_POINT) / (131072 / (2048 - I))) * gb->rate; gb->period_mode3_table[I] = ((1 << FIXED_POINT) / (65536 / (2048 - I))) * gb->rate; } /* Calculate the period table for mode 4 */ for( I = 0; I < 8; I++ ) { for( J = 0; J < 16; J++ ) { /* I is the dividing ratio of frequencies J is the shift clock frequency */ gb->period_mode4_table[I][J] = ((1 << FIXED_POINT) / (524288 / ((I == 0)?0.5:I) / (1 << (J + 1)))) * gb->rate; } } /* Calculate the length table */ for( I = 0; I < 64; I++ ) { gb->length_table[I] = ((64 - I) * ((1 << FIXED_POINT)/256) * gb->rate) >> FIXED_POINT; } /* Calculate the length table for mode 3 */ for( I = 0; I < 256; I++ ) { gb->length_mode3_table[I] = ((256 - I) * ((1 << FIXED_POINT)/256) * gb->rate) >> FIXED_POINT; } gb_sound_w_internal( device, NR52, 0x00 ); gb->snd_regs[AUD3W0] = 0xac; gb->snd_regs[AUD3W1] = 0xdd; gb->snd_regs[AUD3W2] = 0xda; gb->snd_regs[AUD3W3] = 0x48; gb->snd_regs[AUD3W4] = 0x36; gb->snd_regs[AUD3W5] = 0x02; gb->snd_regs[AUD3W6] = 0xcf; gb->snd_regs[AUD3W7] = 0x16; gb->snd_regs[AUD3W8] = 0x2c; gb->snd_regs[AUD3W9] = 0x04; gb->snd_regs[AUD3WA] = 0xe5; gb->snd_regs[AUD3WB] = 0x2c; gb->snd_regs[AUD3WC] = 0xac; gb->snd_regs[AUD3WD] = 0xdd; gb->snd_regs[AUD3WE] = 0xda; gb->snd_regs[AUD3WF] = 0x48; } const device_type GAMEBOY = &device_creator; gameboy_sound_device::gameboy_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : device_t(mconfig, GAMEBOY, "LR35902", tag, owner, clock), device_sound_interface(mconfig, *this) { m_token = global_alloc_array_clear(UINT8, sizeof(gb_sound_t)); } //------------------------------------------------- // device_config_complete - perform any // operations now that the configuration is // complete //------------------------------------------------- void gameboy_sound_device::device_config_complete() { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void gameboy_sound_device::device_start() { DEVICE_START_NAME( gameboy_sound )(this); } //------------------------------------------------- // sound_stream_update - handle a stream update //------------------------------------------------- void gameboy_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) { // should never get here fatalerror("sound_stream_update called; not applicable to legacy sound devices\n"); }