diff --git a/drivers/audio/Win32/gaudout_lld.c b/drivers/audio/Win32/gaudout_lld.c
index 9581fa45..fd70c80b 100644
--- a/drivers/audio/Win32/gaudout_lld.c
+++ b/drivers/audio/Win32/gaudout_lld.c
@@ -64,7 +64,10 @@ static bool_t senddata(WAVEHDR *pwh) {
 	GAudioData *paud;
 
 	// Get the next data block to send
-	if (!(paud = gaudoutGetDataBlockI()))
+	gfxSystemLock();
+	paud = gaudoutGetDataBlockI();
+	gfxSystemUnlock();
+	if (!paud)
 		return FALSE;
 
 	// Prepare the wave header for Windows
@@ -104,7 +107,9 @@ static DWORD WINAPI waveProc(LPVOID arg) {
 				waveOutUnprepareHeader(ah, pwh, sizeof(WAVEHDR));
 
 				// Give the buffer back to the Audio Free List
+				gfxSystemLock();
 				gaudoutReleaseDataBlockI((GAudioData *)pwh->dwUser);
+				gfxSystemUnlock();
 				pwh->lpData = 0;
 				nQueuedBuffers--;
 
@@ -131,9 +136,12 @@ void gaudout_lld_deinit() {
 	}
 }
 
-bool_t gaudout_lld_init(uint16_t channel, uint32_t frequency) {
+bool_t gaudout_lld_init(uint16_t channel, uint32_t frequency, ArrayDataFormat format) {
 	WAVEFORMATEX	wfx;
 
+	if (format != ARRAY_DATA_8BITUNSIGNED && format != ARRAY_DATA_16BITSIGNED)
+		return FALSE;
+
 	if (!waveThread) {
 		if (!(waveThread = CreateThread(0, 0, (LPTHREAD_START_ROUTINE)waveProc, 0, 0, &threadID))) {
 			fprintf(stderr, "GAUDOUT: Can't create WAVE play-back thread\n");
@@ -145,9 +153,9 @@ bool_t gaudout_lld_init(uint16_t channel, uint32_t frequency) {
 	wfx.wFormatTag = WAVE_FORMAT_PCM;
 	wfx.nChannels = channel == GAUDOUT_STEREO ? 2 : 1;
 	wfx.nSamplesPerSec = frequency;
-	wfx.nBlockAlign = wfx.nChannels * sizeof(audout_sample_t);
+	wfx.nBlockAlign = wfx.nChannels * (format == ARRAY_DATA_8BITUNSIGNED ? 1 : 2);
 	wfx.nAvgBytesPerSec = wfx.nSamplesPerSec * wfx.nBlockAlign;
-	wfx.wBitsPerSample = sizeof(audout_sample_t) * 8;
+	wfx.wBitsPerSample = (format == ARRAY_DATA_8BITUNSIGNED ? 8 : 16);
 	wfx.cbSize = 0;
 
 	if (waveOutOpen(&ah, WAVE_MAPPER, &wfx, (DWORD_PTR)threadID, 0, CALLBACK_THREAD)) {
diff --git a/src/gaudout/driver.h b/src/gaudout/driver.h
index cd9ab01b..8e72dff4 100644
--- a/src/gaudout/driver.h
+++ b/src/gaudout/driver.h
@@ -62,12 +62,13 @@ void gaudoutReleaseDataBlockI(GAudioData *paud);
  *
  * @param[in] channel	The channel to use (see the driver for the available channels provided)
  * @param[in] frequency	The sample frequency to use
+ * @param[in] format	The sample format
  *
  * @note				The driver will always have been stopped and de-init before this is called.
  *
  * @api
  */
-bool_t gaudout_lld_init(uint16_t channel, uint32_t frequency);
+bool_t gaudout_lld_init(uint16_t channel, uint32_t frequency, ArrayDataFormat format);
 
 /**
  * @brief				De-Initialise the driver
diff --git a/src/gaudout/gaudout.c b/src/gaudout/gaudout.c
index c0d673a0..275677c8 100644
--- a/src/gaudout/gaudout.c
+++ b/src/gaudout/gaudout.c
@@ -94,10 +94,10 @@ GAudioData *gaudioGetBuffer(delaytime_t ms) {
 	return (GAudioData *)gfxQueueGSyncGet(&freelist, ms);
 }
 
-bool_t gaudioPlayInit(uint16_t channel, uint32_t frequency) {
+bool_t gaudioPlayInit(uint16_t channel, uint32_t frequency, ArrayDataFormat format) {
 	gaudioPlayStop();
 	gaudout_lld_deinit();
-	return gaudout_lld_init(channel, frequency);
+	return gaudout_lld_init(channel, frequency, format);
 }
 
 void gaudioPlay(GAudioData *paud) {
@@ -127,11 +127,11 @@ bool_t gaudioPlaySetVolume(uint8_t vol) {
  */
 
 GAudioData *gaudoutGetDataBlockI(void) {
-	return (GAudioData *)gfxQueueASyncGet(&playlist);
+	return (GAudioData *)gfxQueueASyncGetI(&playlist);
 }
 
 void gaudoutReleaseDataBlockI(GAudioData *paud) {
-	gfxQueueGSyncPut(&freelist, (gfxQueueGSyncItem *)paud);
+	gfxQueueGSyncPutI(&freelist, (gfxQueueGSyncItem *)paud);
 }
 
 
diff --git a/src/gaudout/sys_defs.h b/src/gaudout/sys_defs.h
index c3745b8c..4f09678b 100644
--- a/src/gaudout/sys_defs.h
+++ b/src/gaudout/sys_defs.h
@@ -39,7 +39,7 @@
 typedef struct GAudioData {
 	gfxQueueASyncItem	next;		// @< Used for queuing the buffers
 	size_t				size;		// @< The size of the buffer area following this structure (in bytes)
-	size_t				len;		// @< The length of the data in the buffer area (in samples)
+	size_t				len;		// @< The length of the data in the buffer area (in bytes)
 } GAudioData;
 
 /*===========================================================================*/
@@ -92,13 +92,14 @@ void gaudioReleaseBuffer(GAudioData *paud);
  *
  * @param[in] channel	The audio output channel to use.
  * @param[in] frequency	The audio sample rate in samples per second
+ * @param[in] format	The audio sample format
  *
  * @note		Some channels are mono, and some are stereo. See your driver config file
  * 				to determine which channels to use and whether they are stereo or not.
  *
  * @api
  */
-bool_t gaudioPlayInit(uint16_t channel, uint32_t frequency);
+bool_t gaudioPlayInit(uint16_t channel, uint32_t frequency, ArrayDataFormat format);
 
 /**
  * @brief		Play the specified sample data.
@@ -109,8 +110,7 @@ bool_t gaudioPlayInit(uint16_t channel, uint32_t frequency);
  *
  * @note		Calling this will cancel any pause.
  * @note		Before calling this function the len field of the GAudioData structure must be
- * 				specified. While the buffer size is specified in bytes, this length is specified in samples
- * 				and must be even for stereo channels.
+ * 				specified (in bytes).
  * @note		For stereo channels the sample data is interleaved in the buffer.
  * @note		This call returns before the data has completed playing. Subject to available buffers (which
  * 				can be obtained from the free-list), any number of buffers may be played. They will be queued