/*************************************************************************** meadows.c Sound handler Dead Eye, Gypsy Juggler J. Buchmueller, June '98 ****************************************************************************/ #include "driver.h" #include "cpu/s2650/s2650.h" #include "meadows.h" #include "sound/samples.h" #include "sound/dac.h" UINT8 meadows_0c00 = 0; UINT8 meadows_0c01 = 0; UINT8 meadows_0c02 = 0; UINT8 meadows_0c03 = 0; static UINT8 meadows_dac = 0; static int dac_enable; #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 int channel; static int freq1 = 1000; static int freq2 = 1000; static INT16 waveform[2] = { -120*256, 120*256 }; /************************************/ /* Sound handler start */ /************************************/ void meadows_sh_start(void) { int vol[2]; vol[0]=vol[1]=255; sample_set_volume(0,0); sample_start_raw(0,waveform,sizeof(waveform)/2,freq1,1); sample_set_volume(1,0); sample_start_raw(1,waveform,sizeof(waveform)/2,freq2,1); } /************************************/ /* Sound handler update */ /************************************/ void meadows_sh_update(void) { static UINT8 latched_0c01 = 0; static UINT8 latched_0c02 = 0; static UINT8 latched_0c03 = 0; int preset, amp; if (latched_0c01 != meadows_0c01 || latched_0c03 != meadows_0c03) { /* amplitude is a combination of the upper 4 bits of 0c01 */ /* and bit 4 merged from S2650's flag output */ amp = ((meadows_0c03 & ENABLE_CTR1) == 0) ? 0 : (meadows_0c01 & 0xf0) >> 1; if( activecpu_get_reg(S2650_FO) ) amp += 0x80; /* calculate frequency for counter #1 */ /* bit 0..3 of 0c01 are ctr preset */ preset = (meadows_0c01 & 15) ^ 15; if (preset) freq1 = BASE_CTR1 / (preset + 1); else amp = 0; logerror("meadows ctr1 channel #%d preset:%3d freq:%5d amp:%d\n", channel, preset, freq1, amp); sample_set_freq(0, freq1 * sizeof(waveform)/2); sample_set_volume(0,amp/255.0); } if (latched_0c02 != meadows_0c02 || latched_0c03 != meadows_0c03) { /* calculate frequency for counter #2 */ /* 0c02 is ctr preset, 0c03 bit 0 enables division by 2 */ amp = ((meadows_0c03 & ENABLE_CTR2) != 0) ? 0xa0 : 0; preset = meadows_0c02 ^ 0xff; if (preset) { freq2 = BASE_CTR2 / (preset + 1) / 2; if ((meadows_0c03 & DIV2OR4_CTR2) == 0) freq2 >>= 1; } else amp = 0; logerror("meadows ctr2 channel #%d preset:%3d freq:%5d amp:%d\n", channel+1, preset, freq2, amp); sample_set_freq(1, freq2 * sizeof(waveform)); sample_set_volume(1,amp/255.0); } if (latched_0c03 != meadows_0c03) { dac_enable = meadows_0c03 & ENABLE_DAC; if (dac_enable) DAC_data_w(0, meadows_dac); else DAC_data_w(0, 0); } latched_0c01 = meadows_0c01; latched_0c02 = meadows_0c02; latched_0c03 = meadows_0c03; } /************************************/ /* Write DAC value */ /************************************/ void meadows_sh_dac_w(int data) { meadows_dac = data; if (dac_enable) DAC_data_w(0, meadows_dac); else DAC_data_w(0, 0); }