First attempt at sound

8 files changed, 107 insertions, 8 deletions

diff --git a/include/config.h b/include/config.h
index b57c3ef..800960b 100644
--- a/include/config.h
+++ b/include/config.h
@@ -29,6 +29,7 @@ typedef enum
 {
     DSSPEC_STICKY_SHIFT,
     DSSPEC_LOAD_DEFAULT_SNAPSHOT,
+    DSSPEC_SOUND,
     DSSPEC_NUM_CONFIG_ITEMS
 } DSSPEC_ConfigItem;
 
diff --git a/include/spec.h b/include/spec.h
index 47549a3..85fb5e7 100644
--- a/include/spec.h
+++ b/include/spec.h
@@ -32,6 +32,10 @@
 #include "z80.h"
 #include "keyboard.h"
 
+/* Sample rate for sound emulation
+*/
+#define SAMPLE_RATE     22050
+
 
 /* Initialise the SPEC
 */
diff --git a/include/z80.h b/include/z80.h
index ef24fd0..ab095d8 100644
--- a/include/z80.h
+++ b/include/z80.h
@@ -134,13 +134,23 @@ typedef int	(*Z80Callback)(Z80 *cpu, Z80Val data);
 */
 typedef enum
 {
-    eZ80_Instruction,	/* data = no cycles since reset                       */
+    eZ80_Instruction,	/* data = cycles as returned by Z80Cycles             */
     eZ80_EDHook,	/* data = byte after ED opcode (only for NOP opcodes) */
     eZ80_Halt,		/* data = 1 halt raised, 0 halt cleared by int        */
     eZ80_RETI,		/* data = ignored                                     */
     eZ80_NO_CALLBACK	/* leave at end                                       */
 } Z80CallbackReason;
 
+/* Defines cycle timers
+*/
+typedef enum
+{
+    Z80_TIMER_1,
+    Z80_TIMER_2,
+    Z80_TIMER_3,
+    Z80_NO_TIMERS
+} Z80Timer;
+
 
 /* Flags in the F register
 */
@@ -235,6 +245,11 @@ void	Z80Exec(Z80 *cpu);
 Z80Val	Z80Cycles(Z80 *cpu);
 void	Z80ResetCycles(Z80 *cpu, Z80Val cycles);
 
+/* Timers that count in cycle counts
+*/
+Z80Val  Z80GetTimer(Z80 *cpu, Z80Timer timer);
+void    Z80SetTimer(Z80 *cpu, Z80Timer timer, Z80Val cycles);
+
 
 /* Set address to label mappings for the disassembler
 */
diff --git a/include/z80_private.h b/include/z80_private.h
index 10cf97e..e0b3381 100644
--- a/include/z80_private.h
+++ b/include/z80_private.h
@@ -48,6 +48,8 @@ struct Z80Private
 {
     Z80Val		cycle;
 
+    Z80Val              timer[Z80_NO_TIMERS];
+
     int			halt;
 
     Z80Byte		shift;
@@ -178,7 +180,13 @@ static inline Z80Word PEEKW(Z80Word addr)
 #define IS_IX_IY		(PRIV->shift==0xdd || PRIV->shift==0xfd)
 #define OFFSET(off)		off=(IS_IX_IY ? (Z80Relative)FETCH_BYTE:0)
 
-#define TSTATE(n)		PRIV->cycle+=n
+#define TSTATE(n)		do                                      \
+                                {                                       \
+                                    PRIV->cycle+=n;                     \
+                                    PRIV->timer[Z80_TIMER_1]+=n;        \
+                                    PRIV->timer[Z80_TIMER_2]+=n;        \
+                                    PRIV->timer[Z80_TIMER_3]+=n;        \
+                                } while(0)
 
 #define ADD_R(v)		cpu->R=((cpu->R&0x80)|((cpu->R+(v))&0x7f))
 #define INC_R			ADD_R(1)
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;