diff options
Diffstat (limited to 'trunk/src/mame/audio/meadows.c')
-rw-r--r-- | trunk/src/mame/audio/meadows.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/trunk/src/mame/audio/meadows.c b/trunk/src/mame/audio/meadows.c new file mode 100644 index 00000000000..c4134c1149d --- /dev/null +++ b/trunk/src/mame/audio/meadows.c @@ -0,0 +1,120 @@ +/*************************************************************************** + meadows.c + Sound handler + Dead Eye, Gypsy Juggler + + J. Buchmueller, June '98 +****************************************************************************/ + +#include "emu.h" +#include "cpu/s2650/s2650.h" +#include "includes/meadows.h" +#include "sound/samples.h" +#include "sound/dac.h" + + + +#define BASE_CLOCK 5000000 +#define BASE_CTR1 (BASE_CLOCK / 256) +#define BASE_CTR2 (BASE_CLOCK / 32) + +#define DIV2OR4_CTR2 0x01 +#define ENABLE_CTR2 0x02 +#define ENABLE_DAC 0x04 +#define ENABLE_CTR1 0x08 + +static const INT16 waveform[2] = { -120*256, 120*256 }; + +/************************************/ +/* Sound handler start */ +/************************************/ +SAMPLES_START( meadows_sh_start ) +{ + meadows_state *state = device.machine().driver_data<meadows_state>(); + state->m_0c00 = state->m_0c01 = state->m_0c02 = state->m_0c03 = 0; + state->m_dac = 0; + state->m_dac_enable = 0; + state->m_channel = 0; + state->m_freq1 = state->m_freq2 = 1000; + state->m_latched_0c01 = state->m_latched_0c02 = state->m_latched_0c03 = 0; + + device.set_volume(0,0); + device.start_raw(0,waveform,ARRAY_LENGTH(waveform),state->m_freq1,true); + device.set_volume(1,0); + device.start_raw(1,waveform,ARRAY_LENGTH(waveform),state->m_freq2,true); +} + +/************************************/ +/* Sound handler update */ +/************************************/ +void meadows_sh_update(running_machine &machine) +{ + meadows_state *state = machine.driver_data<meadows_state>(); + samples_device *samples = machine.device<samples_device>("samples"); + int preset, amp; + + if (state->m_latched_0c01 != state->m_0c01 || state->m_latched_0c03 != state->m_0c03) + { + /* amplitude is a combination of the upper 4 bits of 0c01 */ + /* and bit 4 merged from S2650's flag output */ + amp = ((state->m_0c03 & ENABLE_CTR1) == 0) ? 0 : (state->m_0c01 & 0xf0) >> 1; + if( cpu_get_reg(machine.device("maincpu"), S2650_FO) ) + amp += 0x80; + /* calculate frequency for counter #1 */ + /* bit 0..3 of 0c01 are ctr preset */ + preset = (state->m_0c01 & 15) ^ 15; + if (preset) + state->m_freq1 = BASE_CTR1 / (preset + 1); + else amp = 0; + logerror("meadows ctr1 channel #%d preset:%3d freq:%5d amp:%d\n", state->m_channel, preset, state->m_freq1, amp); + samples->set_frequency(0, state->m_freq1 * sizeof(waveform)/2); + samples->set_volume(0,amp/255.0); + } + + if (state->m_latched_0c02 != state->m_0c02 || state->m_latched_0c03 != state->m_0c03) + { + /* calculate frequency for counter #2 */ + /* 0c02 is ctr preset, 0c03 bit 0 enables division by 2 */ + amp = ((state->m_0c03 & ENABLE_CTR2) != 0) ? 0xa0 : 0; + preset = state->m_0c02 ^ 0xff; + if (preset) + { + state->m_freq2 = BASE_CTR2 / (preset + 1) / 2; + if ((state->m_0c03 & DIV2OR4_CTR2) == 0) + state->m_freq2 >>= 1; + } + else amp = 0; + logerror("meadows ctr2 channel #%d preset:%3d freq:%5d amp:%d\n", state->m_channel+1, preset, state->m_freq2, amp); + samples->set_frequency(1, state->m_freq2 * sizeof(waveform)); + samples->set_volume(1,amp/255.0); + } + + if (state->m_latched_0c03 != state->m_0c03) + { + state->m_dac_enable = state->m_0c03 & ENABLE_DAC; + + if (state->m_dac_enable) + dac_data_w(machine.device("dac"), state->m_dac); + else + dac_data_w(machine.device("dac"), 0); + } + + state->m_latched_0c01 = state->m_0c01; + state->m_latched_0c02 = state->m_0c02; + state->m_latched_0c03 = state->m_0c03; +} + +/************************************/ +/* Write DAC value */ +/************************************/ +void meadows_sh_dac_w(running_machine &machine, int data) +{ + meadows_state *state = machine.driver_data<meadows_state>(); + state->m_dac = data; + if (state->m_dac_enable) + dac_data_w(machine.device("dac"), state->m_dac); + else + dac_data_w(machine.device("dac"), 0); +} + + |