MSM6258: start work - DO NOT USE!

src/engine/platform/sound/oki/okim6258.cpp

@@ -12,6 +12,7 @@
 
 
 #include "okim6258.h"
+#include <stdio.h>
 #include <string.h>
 #include <math.h>
 
@@ -113,6 +114,7 @@ void okim6258_device::device_start()
 
 	m_signal = -2;
 	m_step = 0;
+  m_has_data = false;
 }
 
 
@@ -125,6 +127,7 @@ void okim6258_device::device_reset()
 	m_signal = -2;
 	m_step = 0;
 	m_status = 0;
+  m_has_data = false;
 }
 
 
@@ -150,6 +153,8 @@ void okim6258_device::sound_stream_update(short** outputs, int len)
 
 			nibble_shift ^= 4;
 
+      if (nibble_shift==0) m_has_data=false;
+
 			buffer[sampindex]=sample;
 		}
 
@@ -241,10 +246,13 @@ uint8_t okim6258_device::status_r()
      okim6258_data_w -- write to the control port of an OKIM6258-compatible chip
 
 ***********************************************************************************************/
-void okim6258_device::data_w(uint8_t data)
+bool okim6258_device::data_w(uint8_t data)
 {
+  if (m_has_data) return false;
 	m_data_in = data;
 	m_nibble_shift = 0;
+  m_has_data = true;
+  return true;
 }
 
 
@@ -259,6 +267,8 @@ void okim6258_device::ctrl_w(uint8_t data)
 	if (data & COMMAND_STOP)
 	{
 		m_status &= ~(STATUS_PLAYING | STATUS_RECORDING);
+    m_has_data = false;
+    printf("stopping\n");
 		return;
 	}
 
@@ -272,6 +282,7 @@ void okim6258_device::ctrl_w(uint8_t data)
 			m_signal = -2;
 			m_step = 0;
 			m_nibble_shift = 0;
+      printf("playing\n");
 		}
 	}
 	else

src/engine/platform/sound/oki/okim6258.h

@@ -31,19 +31,19 @@ public:
 	void set_outbits(int outbit) { m_output_bits = outbit; }
 
 	uint8_t status_r();
-	void data_w(uint8_t data);
+	bool data_w(uint8_t data);
 	void ctrl_w(uint8_t data);
 
 	void set_divider(int val);
 	int get_vclk();
 
 	// device-levels
-	virtual void device_start();
-	virtual void device_reset();
-	virtual void device_clock_changed();
+	void device_start();
+	void device_reset();
+	void device_clock_changed();
 
 	// sound stream updates
-	virtual void sound_stream_update(short** outputs, int len);
+	void sound_stream_update(short** outputs, int len);
 
 private:
 	int16_t clock_adpcm(uint8_t nibble);
@@ -54,6 +54,7 @@ private:
 	uint32_t m_divider;         /* master clock divider */
 	uint8_t m_adpcm_type;       /* 3/4 bit ADPCM select */
 	uint8_t m_data_in;          /* ADPCM data-in register */
+  bool m_has_data;            /* whether we already have data */
 	uint8_t m_nibble_shift;     /* nibble select */
 
 	uint8_t m_output_bits;      /* D/A precision is 10-bits but 12-bit data can be