// license:BSD-3-Clause // copyright-holders:K.Wilkins /*************************************************************************** Lunar Lander Specific Sound Code ***************************************************************************/ #include "emu.h" #include "includes/asteroid.h" #include "sound/discrete.h" #include "speaker.h" /************************************************************************/ /* Lunar Lander Sound System Analog emulation by K.Wilkins Nov 2000 */ /* Questions/Suggestions to mame@esplexo.co.uk */ /************************************************************************/ #define LLANDER_TONE3K_EN NODE_01 #define LLANDER_TONE6K_EN NODE_02 #define LLANDER_THRUST_DATA NODE_03 #define LLANDER_EXPLOD_EN NODE_04 #define LLANDER_NOISE_RESET NODE_05 #define LLANDER_NOISE NODE_10 #define LLANDER_TONE_3K_SND NODE_11 #define LLANDER_TONE_6K_SND NODE_12 #define LLANDER_THRUST_EXPLOD_SND NODE_13 static const discrete_lfsr_desc llander_lfsr = { DISC_CLK_IS_FREQ, 16, /* Bit Length */ 0, /* Reset Value */ 6, /* Use Bit 6 as XOR input 0 */ 14, /* Use Bit 14 as XOR input 1 */ DISC_LFSR_XNOR, /* Feedback stage1 is inverted XOR */ DISC_LFSR_IN0, /* Feedback stage2 is just stage 1 output external feed not used */ DISC_LFSR_REPLACE, /* Feedback stage3 replaces the shifted register contents */ 0x000001, /* Everything is shifted into the first bit only */ 0, /* Output not inverted */ 14 /* Output bit */ }; static DISCRETE_SOUND_START(llander_discrete) /************************************************/ /* llander Effects Relataive Gain Table */ /* */ /* Effect V-ampIn Gain ratio Relative */ /* Tone3k 4 10/390 9.2 */ /* Tone6k 4 10/390 9.2 */ /* Explode 3.8 10/6.8*2 1000.0 */ /* Thrust 3.8 10/6.8*2 600.0 */ /* NOTE: Thrust gain has to be tweaked, due to */ /* the filter stage. */ /************************************************/ /* NODE GAIN OFFSET INIT */ DISCRETE_INPUTX_DATA(LLANDER_THRUST_DATA, 600.0/7*7.6, 0, 0) DISCRETE_INPUT_LOGIC(LLANDER_TONE3K_EN) DISCRETE_INPUT_LOGIC(LLANDER_TONE6K_EN) DISCRETE_INPUT_LOGIC(LLANDER_EXPLOD_EN) DISCRETE_INPUT_PULSE(LLANDER_NOISE_RESET, 1) DISCRETE_LFSR_NOISE(NODE_20, 1, LLANDER_NOISE_RESET, 12000, 1, 0, 0, &llander_lfsr) // 12KHz Noise source for thrust DISCRETE_RCFILTER(LLANDER_NOISE, NODE_20, 2247, 1e-6) DISCRETE_SQUAREWFIX(LLANDER_TONE_3K_SND, LLANDER_TONE3K_EN, 3000, 9.2, 50, 0, 0) // 3KHz DISCRETE_SQUAREWFIX(LLANDER_TONE_6K_SND, LLANDER_TONE6K_EN, 6000, 9.2, 50, 0, 0) // 6KHz DISCRETE_MULTIPLY(NODE_30, LLANDER_NOISE, LLANDER_THRUST_DATA) // Mix in 12KHz Noise source for thrust /* TBD - replace this line with a Sallen-Key Bandpass macro */ DISCRETE_FILTER2(NODE_31, 1, NODE_30, 89.5, (1.0 / 7.6), DISC_FILTER_BANDPASS) DISCRETE_MULTIPLY(NODE_32, NODE_30, 1000.0/600.0) // Explode adds original noise source onto filtered source DISCRETE_ONOFF(NODE_33, LLANDER_EXPLOD_EN, NODE_32) DISCRETE_ADDER2(NODE_34, 1, NODE_31, NODE_33) /* TBD - replace this line with a Active Lowpass macro */ DISCRETE_FILTER1(LLANDER_THRUST_EXPLOD_SND, 1, NODE_34, 560, DISC_FILTER_LOWPASS) DISCRETE_ADDER3(NODE_90, 1, LLANDER_TONE_3K_SND, LLANDER_TONE_6K_SND, LLANDER_THRUST_EXPLOD_SND) // Mix all four sound sources DISCRETE_GAIN(NODE_91, NODE_90, 65534.0/(9.2+9.2+600+1000)) DISCRETE_OUTPUT(NODE_90, 65534.0/(9.2+9.2+600+1000)) // Take the output from the mixer DISCRETE_SOUND_END WRITE8_MEMBER(asteroid_state::llander_snd_reset_w) { /* Resets the LFSR that is used for the white noise generator */ m_discrete->write(space, LLANDER_NOISE_RESET, 0); /* Reset */ } WRITE8_MEMBER(asteroid_state::llander_sounds_w) { m_discrete->write(space, LLANDER_THRUST_DATA, data & 0x07); /* Thrust volume */ m_discrete->write(space, LLANDER_TONE3K_EN, data & 0x10); /* Tone 3KHz enable */ m_discrete->write(space, LLANDER_TONE6K_EN, data & 0x20); /* Tone 6KHz enable */ m_discrete->write(space, LLANDER_EXPLOD_EN, data & 0x08); /* Explosion */ } MACHINE_CONFIG_START(asteroid_state::llander_sound) SPEAKER(config, "mono").front_center(); MCFG_DEVICE_ADD("discrete", DISCRETE, llander_discrete) MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 1.0) MACHINE_CONFIG_END