First attempt at sound

4 files changed, 77 insertions, 6 deletions

diff --git a/source/config.c b/source/config.c
index 8198290..b16f1b3 100644
--- a/source/config.c
+++ b/source/config.c
@@ -40,7 +40,8 @@ const char *conf_filename = "SPEC48.CFG";
 const char *conf_entry[DSSPEC_NUM_CONFIG_ITEMS]=
 {
     "sticky_shift",
-    "load_default_snapshot"
+    "load_default_snapshot",
+    "sound"
 };
 
 
@@ -49,7 +50,8 @@ const char *conf_entry[DSSPEC_NUM_CONFIG_ITEMS]=
 int	DSSPEC_Config[DSSPEC_NUM_CONFIG_ITEMS]=
 {
     TRUE,
-    FALSE
+    FALSE,
+    TRUE
 };
 
 
@@ -126,6 +128,9 @@ const char *ConfigDesc(DSSPEC_ConfigItem item)
 	case DSSPEC_LOAD_DEFAULT_SNAPSHOT:
 	    return "LOAD DEFAULT SNAPSHOT";
 
+	case DSSPEC_SOUND:
+	    return "SOUND";
+
     	default:
 	    return "UNKNOWN";
     }
diff --git a/source/main.c b/source/main.c
index 46eccfe..b7d3318 100644
--- a/source/main.c
+++ b/source/main.c
@@ -235,8 +235,16 @@ int main(int argc, char *argv[])
 {
     Z80 *z80;
     int quit = FALSE;
+    float mix[12] = {1.0, 1.0};
 
     gfxInit(GSP_RGB565_OES, GSP_RGB565_OES, FALSE);
+    ndspInit();
+
+    ndspSetOutputMode(NDSP_OUTPUT_MONO);
+    ndspChnSetInterp(0, NDSP_INTERP_NONE);
+    ndspChnSetRate(0, SAMPLE_RATE);
+    ndspChnSetFormat(0, NDSP_FORMAT_MONO_PCM8);
+    ndspChnSetMix(0, mix);
 
     FB_Init();
 
@@ -352,6 +360,7 @@ int main(int argc, char *argv[])
 	}
     }
 
+    ndspExit();
     gfxExit();
 
     return 0;
diff --git a/source/spec.c b/source/spec.c
index 6cdc7c6..ef132d4 100644
--- a/source/spec.c
+++ b/source/spec.c
@@ -59,6 +59,7 @@
 #define ED_LOAD		0xf1
 
 #define SCAN_CYCLES     224
+#define FRAME_CYCLES    69888
 
 /* The 3DS screen
 */
@@ -153,6 +154,17 @@ static struct
     	{7,0x10}, {7,0x08}, {7,0x04}, {7,0x02}, {7,0x01} 	/* B - SPACE */
     };
 
+/* Sound
+*/
+#define SAMPLE_BUFF_SZ  (SAMPLE_RATE/60)
+
+#define SAMPLE_CYCLE    (FRAME_CYCLES/SAMPLE_BUFF_SZ)
+
+static u8               *sample[2];
+static int              sound_buffer;
+static u8               sound_level;
+static int              sound_ptr;
+static ndspWaveBuf      wave_buff[2];
 
 /* ---------------------------------------- PRIVATE FUNCTIONS
 */
@@ -160,7 +172,7 @@ static void RomPatch(void)
 {
     static const Z80Byte save[]=
     {
-    	0xed, ED_SAVE,		/* (SAVE)		*/
+        0xed, ED_SAVE,		/* (SAVE)		*/
 	0xc9,                   /* RET		        */
 	0xff			/* End of patch		*/
     };
@@ -263,6 +275,13 @@ static int CheckTimers(Z80 *z80, Z80Val val)
 {
     int ret = TRUE;
 
+    if (DSSPEC_Config[DSSPEC_SOUND] &&
+                Z80GetTimer(z80, Z80_TIMER_1) >= SAMPLE_CYCLE)
+    {
+        Z80SetTimer(z80, Z80_TIMER_1, 0);
+        sample[sound_buffer][sound_ptr++] = sound_level;
+    }
+
     if (val > SCAN_CYCLES)
     {
         int y;
@@ -287,6 +306,15 @@ static int CheckTimers(Z80 *z80, Z80Val val)
 
 	    Z80Interrupt(z80,0xff);
 
+            if (DSSPEC_Config[DSSPEC_SOUND])
+            {
+                ndspChnWaveBufAdd(0, wave_buff + sound_buffer);
+                sound_buffer = !sound_buffer;
+                memset(sample[sound_buffer], 0, SAMPLE_BUFF_SZ);
+                sound_ptr = 0;
+                Z80SetTimer(z80, Z80_TIMER_1, 0);
+            }
+
             ret = FALSE;
 	}
 
@@ -298,8 +326,6 @@ static int CheckTimers(Z80 *z80, Z80Val val)
         {
             DrawScanline(y, scanline);
         }
-
-	/* TODO: Process sound emulation */
     }
 
     return ret;
@@ -361,6 +387,18 @@ void SPECInit(Z80 *z80)
     Z80LodgeCallback(z80,eZ80_EDHook,EDCallback);
     Z80LodgeCallback(z80,eZ80_Instruction,CheckTimers);
 
+    /* Create sound buffers and wave vars
+    */
+    sample[0] = linearAlloc(SAMPLE_BUFF_SZ);
+    sample[1] = linearAlloc(SAMPLE_BUFF_SZ);
+
+    wave_buff[0].data_vaddr = sample[0];
+    wave_buff[0].nsamples = SAMPLE_BUFF_SZ;
+    wave_buff[1].data_vaddr = sample[1];
+    wave_buff[1].nsamples = SAMPLE_BUFF_SZ;
+
+    sound_buffer = 0;
+
     SPECReset(z80);
 }
 
@@ -465,6 +503,7 @@ void SPECWritePort(Z80 *z80, Z80Word port, Z80Byte val)
     {
 	case 0xfe:	/* ULA */
 	    border = val & 0x07;
+            sound_level = val & 0x10 ? 128:0;
 	    break;
 
 	case 0xfb:	/* ZX Printer */
@@ -486,11 +525,13 @@ void SPECReset(Z80 *z80)
     	matrix[f]=0x1f;
 
     Z80Reset(z80);
-    Z80ResetCycles(z80,0);
 
     border = 0;
     scanline = 0;
 
+    sound_buffer = 0;
+    sound_ptr = 0;
+
     /* Set up screen
     */
     c=0;
diff --git a/source/z80.c b/source/z80.c
index e5f6c92..790aeec 100644
--- a/source/z80.c
+++ b/source/z80.c
@@ -170,6 +170,10 @@ Z80     *Z80Init(Z80ReadMemory read_memory,
 void Z80Reset(Z80 *cpu)
 {
     PRIV->cycle=0;
+    PRIV->timer[Z80_TIMER_1]=0;
+    PRIV->timer[Z80_TIMER_2]=0;
+    PRIV->timer[Z80_TIMER_3]=0;
+
     cpu->PC=0;
 
     cpu->AF.w=0xffff;
@@ -209,6 +213,18 @@ void Z80ResetCycles(Z80 *cpu, Z80Val cycles)
 }
 
 
+Z80Val Z80GetTimer(Z80 *cpu, Z80Timer timer)
+{
+    return PRIV->timer[timer];
+}
+
+
+void Z80SetTimer(Z80 *cpu, Z80Timer timer, Z80Val cycles)
+{
+    PRIV->timer[timer] = cycles;
+}
+
+
 int Z80LodgeCallback(Z80 *cpu, Z80CallbackReason reason, Z80Callback callback)
 {
     int f;