shithub: sms

--- a/Makefile

+++ b/Makefile

@@ -4,7 +4,7 @@

 CFLAGS += -g -O3 -fPIC -flto

 LDFLAGS += -flto

-OBJ = sms.o z80.o mem.o vdp.o

+OBJ = sms.o z80.o mem.o vdp.o psg.o

 .DEFAULT_GOAL := $(TARGET)

--- a/dat.h

+++ b/dat.h

@@ -52,12 +52,11 @@

 enum {

 	FREQ = 53203400,

-	YMDIV = 7 * 6,

-	CPUDIV = 7,

 	Z80DIV = 15,

 	RATE = 44100,

-	SAMPDIV = FREQ / RATE,

 	SAVEFREQ = FREQ / 4,

+	PSGCLOCK = 3579545,

+	PSGDIV = 16,

};

 enum {

--- a/fns.h

+++ b/fns.h

@@ -8,7 +8,6 @@

 uint8_t z80in(uint8_t);

 void z80out(uint8_t, uint8_t);

 void flush(void);

-void audioout(void);

 void vdpmode(void);

 void vdpctrl(uint8_t);

 void vdpdata(uint8_t);

@@ -18,3 +17,6 @@

 uint8_t vdphcounter(void);

 uint8_t vdpvcounter(void);

 void cramwrite(uint16_t, uint8_t);

+void psginit(const uint16_t, const int);

+void psgwrite(const uint8_t);

+uint16_t psgstep();

--- a/mem.c

+++ b/mem.c

@@ -157,6 +157,7 @@

 	}else if ((port >= 0x40) && (port < 0x80)){

 		// printf("  write to SN76489 PSG\n");

+		psgwrite(v);

 	}else if ((port >= 0x80) && (port < 0xC0)){

 		// printf("  write to VDP\n");

 		if ((port & 0x01) == 0x00)

--- /dev/null

+++ b/psg.c

@@ -1,0 +1,96 @@

+#include <stdint.h>

+#include <stdbool.h>

+#include <stdio.h>

+#include "dat.h"

+#define NOISE_TAPPED 0x9

+static const uint8_t noise_table[3] = { 0x10, 0x20, 0x40 };

+static const short vol_table[16] = {

+	8191, 6507, 5168, 4105, 3261, 2590, 2057,

+	1642, 1298, 1031, 819, 650, 516, 410, 326, 0

+};

+static double cyclespersample;

+static double cycles;

+static uint16_t freqreg[4];

+static uint16_t countreg[4];

+static uint8_t attn[4];

+static bool flipflop[4];

+static uint16_t noise;

+static uint8_t curr_reg;

+static uint8_t curr_type;

+void

+psginit(const uint16_t rate, const int clockspd)

+{

+	cyclespersample = (double)clockspd / (double)PSGDIV/ (double)rate;

+	cycles = cyclespersample;

+}

+void

+psgwrite(const uint8_t data)

+{

+	bool first = data & 128;

+	if(first){

+		curr_reg = (data >> 5) & 3;

+		curr_type = (data >> 4) & 1;

+	}

+	if(curr_type){

+		attn[curr_reg] = data & 0x0F;

+	}else if(first && curr_reg == 3){

+		freqreg[3] = data & 7;

+		noise = 0x8000;

+	}

+	else if(first)

+		freqreg[curr_reg] = (freqreg[curr_reg] & 0x3F0) | (data & 0x0F);

+	else

+		countreg[curr_reg] = freqreg[curr_reg] = (freqreg[curr_reg] & 0x0F) | ((data & 0x3F) << 4);

+}

+static inline uint16_t

+parity(uint16_t v)

+{

+	v ^= v >> 8;

+	v ^= v >> 4;

+	v ^= v >> 2;

+	v ^= v >> 1;

+	v &= 1;

+	return v;

+}

+static inline uint16_t

+vol(uint8_t chn)

+{

+	return (flipflop[chn] ? 1 : -1) * vol_table[attn[chn]];

+}

+int16_t

+psgstep()

+{

+	while(cycles > 0){

+		for(uint8_t i = 0; i < 4; i++){

+			countreg[i]--;

+			if(!countreg[i]){

+				if(i < 3){

+					countreg[i] = freqreg[i];

+					flipflop[i] = !flipflop[i];

+				}else{

+					uint8_t nf = freqreg[3] & 3;

+					uint8_t fb = (freqreg[3] >> 2) & 1;

+					countreg[3] = nf == 3 ? freqreg[2] : (0x10 << nf);

+					noise = (noise >> 1) | ((fb ? parity(noise & NOISE_TAPPED) : noise & 1) << 15);

+					flipflop[3] = (noise & 1);

+				}

+			}

+		}

+		cycles--;

+	}

+	cycles += cyclespersample;

+	return vol(0) + vol(1) + vol(2) + vol(3);

+}

--- a/sms.c

+++ b/sms.c

@@ -1,4 +1,5 @@

 #include <fcntl.h>

+#include <stdint.h>

 #include <stdio.h>

 #include <stdlib.h>

 #include <string.h>

@@ -10,7 +11,7 @@

 static retro_input_poll_t input_poll_cb;

 static retro_video_refresh_t video_cb;

 static retro_environment_t environ_cb;

-retro_audio_sample_batch_t audio_cb;

+retro_audio_sample_t audio_cb;

 int t = 0;

 uint32_t r[16];

@@ -21,6 +22,7 @@

 uint8_t *mem = NULL;

 uint8_t *pic = NULL;

 int vdpclock = 0;

+int psgclock = 0;

 uint8_t keys[2];

 void

@@ -53,7 +55,7 @@

 retro_get_system_av_info(struct retro_system_av_info *info)

 	info->timing.fps = 60.0;

-	info->timing.sample_rate = 48000;

+	info->timing.sample_rate = RATE;

 	info->geometry.base_width = 320;

 	info->geometry.base_height = 224;

@@ -77,6 +79,7 @@

 		return false;

 	loadrom(game->data);

+	psginit(RATE, PSGCLOCK);

 	vdpmode();

 	return true;

@@ -108,6 +111,7 @@

 int counter = 0;

 int total = 0;

+int samplescounter = 0;

 void

 retro_run(void)

@@ -143,7 +147,15 @@

 	video_cb(pic, 256, 192, 320*4);

-	audioout();

+	for(int i = 0; i < 736; i++){

+		int16_t frame = psgstep();

+		audio_cb(frame, frame);

+		samplescounter++;

+	}

+	//printf("Samples: %d\n", samplescounter);

+	samplescounter = 0;

 	doflush = 0;

 	total = 0;

@@ -154,15 +166,7 @@

 	doflush = 1;

-static int16_t samples[736 * 2 * 2] = {0};

 void

-audioout(void)

-{

-	audio_cb(samples, 736);

-}

-void

 retro_set_input_poll(retro_input_poll_t cb)

 	input_poll_cb = cb;

@@ -187,7 +191,7 @@

 void

-retro_set_audio_sample_batch(retro_audio_sample_batch_t cb)

+retro_set_audio_sample(retro_audio_sample_t cb)

 	audio_cb = cb;

@@ -221,7 +225,7 @@

 void * retro_get_memory_data(unsigned id) { return NULL; }

 void retro_unload_game(void) {}

 void retro_deinit(void) {}

-void retro_set_audio_sample(retro_audio_sample_t cb) {}

+void retro_set_audio_sample_batch(retro_audio_sample_batch_t cb) {}

 void retro_cheat_reset(void) {}

 void retro_cheat_set(unsigned index, bool enabled, const char *code) {}

 bool retro_load_game_special(unsigned game_type, const struct retro_game_info *info, size_t num_info) { return false; }

--- a/z80.c

+++ b/z80.c

@@ -676,7 +676,7 @@

 		return 1;

 	if(z80irq != 0 && (intm & 0x80) != 0){

-		printf("irq\n");

+		//printf("irq\n");

 		push16(pc);

 		intm &= 0x3f;

 		switch(intm & 3){

--

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