#include #include #include #include #include #include #include <86box/86box.h> #include <86box/io.h> #include <86box/device.h> #include <86box/sound.h> #include <86box/snd_sn76489.h> int sn76489_mute; static float volslog[16]= { 0.00000f,0.59715f,0.75180f,0.94650f, 1.19145f,1.50000f,1.88835f,2.37735f, 2.99295f,3.76785f,4.74345f,5.97165f, 7.51785f,9.46440f,11.9194f,15.0000f }; void sn76489_update(sn76489_t *sn76489) { for (; sn76489->pos < sound_pos_global; sn76489->pos++) { int c; int16_t result = 0; for (c = 1; c < 4; c++) { if (sn76489->latch[c] > 256) result += (int16_t) (volslog[sn76489->vol[c]] * sn76489->stat[c]); else result += (int16_t) (volslog[sn76489->vol[c]] * 127); sn76489->count[c] -= (256 * sn76489->psgconst); while ((int)sn76489->count[c] < 0) { sn76489->count[c] += sn76489->latch[c]; sn76489->stat[c] = -sn76489->stat[c]; } } result += (((sn76489->shift & 1) ^ 1) * 127 * volslog[sn76489->vol[0]] * 2); sn76489->count[0] -= (512 * sn76489->psgconst); while ((int)sn76489->count[0] < 0 && sn76489->latch[0]) { sn76489->count[0] += (sn76489->latch[0] * 4); if (!(sn76489->noise & 4)) { if (sn76489->shift & 1) sn76489->shift |= 0x8000; sn76489->shift >>= 1; } else { if ((sn76489->shift & 1) ^ ((sn76489->shift >> 1) & 1)) sn76489->shift |= 0x8000; sn76489->shift >>= 1; } } sn76489->buffer[sn76489->pos] = result; } } void sn76489_get_buffer(int32_t *buffer, int len, void *p) { sn76489_t *sn76489 = (sn76489_t *)p; int c; sn76489_update(sn76489); if (!sn76489_mute) { for (c = 0; c < len * 2; c++) buffer[c] += sn76489->buffer[c >> 1]; } sn76489->pos = 0; } void sn76489_write(uint16_t addr, uint8_t data, void *p) { sn76489_t *sn76489 = (sn76489_t *)p; int freq; sn76489_update(sn76489); if (data & 0x80) { sn76489->firstdat = data; switch (data & 0x70) { case 0: sn76489->freqlo[3] = data & 0xf; sn76489->latch[3] = (sn76489->freqlo[3] | (sn76489->freqhi[3] << 4)) << 6; if (sn76489->extra_divide) sn76489->latch[3] &= 0x3ff; if (!sn76489->latch[3]) sn76489->latch[3] = (sn76489->extra_divide ? 2048 : 1024) << 6; sn76489->lasttone = 3; break; case 0x10: data &= 0xf; sn76489->vol[3] = 0xf - data; break; case 0x20: sn76489->freqlo[2] = data & 0xf; sn76489->latch[2] = (sn76489->freqlo[2] | (sn76489->freqhi[2] << 4)) << 6; if (sn76489->extra_divide) sn76489->latch[2] &= 0x3ff; if (!sn76489->latch[2]) sn76489->latch[2] = (sn76489->extra_divide ? 2048 : 1024) << 6; sn76489->lasttone = 2; break; case 0x30: data &= 0xf; sn76489->vol[2] = 0xf - data; break; case 0x40: sn76489->freqlo[1] = data & 0xf; sn76489->latch[1] = (sn76489->freqlo[1] | (sn76489->freqhi[1] << 4)) << 6; if (sn76489->extra_divide) sn76489->latch[1] &= 0x3ff; if (!sn76489->latch[1]) sn76489->latch[1] = (sn76489->extra_divide ? 2048 : 1024) << 6; sn76489->lasttone = 1; break; case 0x50: data &= 0xf; sn76489->vol[1] = 0xf - data; break; case 0x60: if ((data & 4) != (sn76489->noise & 4) || sn76489->type == SN76496) sn76489->shift = 0x4000; sn76489->noise = data & 0xf; if ((data & 3) == 3) sn76489->latch[0] = sn76489->latch[1]; else sn76489->latch[0] = 0x400 << (data & 3); if (sn76489->extra_divide) sn76489->latch[0] &= 0x3ff; if (!sn76489->latch[0]) sn76489->latch[0] = (sn76489->extra_divide ? 2048 : 1024) << 6; break; case 0x70: data &= 0xf; sn76489->vol[0] = 0xf - data; break; } } else { if ((sn76489->firstdat & 0x70) == 0x60 && (sn76489->type == SN76496)) { if ((data & 4) != (sn76489->noise & 4) || sn76489->type == SN76496) sn76489->shift = 0x4000; sn76489->noise = data & 0xf; if ((data & 3) == 3) sn76489->latch[0] = sn76489->latch[1]; else sn76489->latch[0] = 0x400 << (data & 3); if (!sn76489->latch[0]) sn76489->latch[0] = 1024 << 6; } else if ((sn76489->firstdat & 0x70) != 0x60) { sn76489->freqhi[sn76489->lasttone] = data & 0x7F; freq = sn76489->freqlo[sn76489->lasttone] | (sn76489->freqhi[sn76489->lasttone] << 4); if (sn76489->extra_divide) freq &= 0x3ff; if (!freq) freq = sn76489->extra_divide ? 2048 : 1024; if ((sn76489->noise & 3) == 3 && sn76489->lasttone == 1) sn76489->latch[0] = freq << 6; sn76489->latch[sn76489->lasttone] = freq << 6; } } } void sn74689_set_extra_divide(sn76489_t *sn76489, int enable) { sn76489->extra_divide = enable; } void sn76489_init(sn76489_t *sn76489, uint16_t base, uint16_t size, int type, int freq) { sound_add_handler(sn76489_get_buffer, sn76489); sn76489->latch[0] = sn76489->latch[1] = sn76489->latch[2] = sn76489->latch[3] = 0x3FF << 6; sn76489->vol[0] = 0; sn76489->vol[1] = sn76489->vol[2] = sn76489->vol[3] = 8; sn76489->stat[0] = sn76489->stat[1] = sn76489->stat[2] = sn76489->stat[3] = 127; srand(time(NULL)); sn76489->count[0] = 0; sn76489->count[1] = (rand()&0x3FF)<<6; sn76489->count[2] = (rand()&0x3FF)<<6; sn76489->count[3] = (rand()&0x3FF)<<6; sn76489->noise = 3; sn76489->shift = 0x4000; sn76489->type = type; sn76489->psgconst = (((double)freq / 64.0) / 48000.0); sn76489_mute = 0; io_sethandler(base, size, NULL, NULL, NULL, sn76489_write, NULL, NULL, sn76489); } void *sn76489_device_init(const device_t *info) { sn76489_t *sn76489 = malloc(sizeof(sn76489_t)); memset(sn76489, 0, sizeof(sn76489_t)); sn76489_init(sn76489, 0x00c0, 0x0008, SN76496, 3579545); return sn76489; } void *ncr8496_device_init(const device_t *info) { sn76489_t *sn76489 = malloc(sizeof(sn76489_t)); memset(sn76489, 0, sizeof(sn76489_t)); sn76489_init(sn76489, 0x00c0, 0x0008, NCR8496, 3579545); return sn76489; } void sn76489_device_close(void *p) { sn76489_t *sn76489 = (sn76489_t *)p; free(sn76489); } const device_t sn76489_device = { "TI SN74689 PSG", 0, 0, sn76489_device_init, sn76489_device_close, NULL, { NULL }, NULL, NULL }; const device_t ncr8496_device = { "NCR8496 PSG", 0, 0, ncr8496_device_init, sn76489_device_close, NULL, { NULL }, NULL, NULL };