diff --git a/src/core.h b/src/core.h
index 50078e1..1a2488e 100644
--- a/src/core.h
+++ b/src/core.h
@@ -31,6 +31,7 @@
 
     extern void osToggleVR(bool enable);
 #elif __SDL2__
+    extern void osToggleVR(bool enable);
     #define _GAPI_GL   1
 #ifdef SDL2_GLES
     #define _GAPI_GLES 1
diff --git a/src/platform/sdl2/main.cpp b/src/platform/sdl2/main.cpp
index 9a098c0..2034ecf 100644
--- a/src/platform/sdl2/main.cpp
+++ b/src/platform/sdl2/main.cpp
@@ -20,8 +20,9 @@ int osGetTimeMS() {
 }
 
 // sound
+#define SND_FRAME_SIZE  4
+#define SND_FRAMES      1024
 
-int SND_FRAMES = 512;
 // A Frame is a struct containing: int16 L, int16 R.
 Sound::Frame        *sndData;
 SDL_AudioDeviceID sdl_audiodev;
@@ -29,9 +30,9 @@ SDL_AudioDeviceID sdl_audiodev;
 void sndFill(void *udata, Uint8 *stream, int len) {
         // Let's milk the audio subsystem for SND_FRAMES frames!
         Sound::fill(sndData, SND_FRAMES);
-        // We have the number of samples, but each sample is sizeof(Sound::Frame) bytes long,
+        // We have the number of samples, but each sample is 4 bytes long (16bit stereo sound),
         // and memcpy copies a number of bytes.
-        memcpy (stream, sndData, SND_FRAMES * sizeof(Sound::Frame));
+        memcpy (stream, sndData, SND_FRAMES * SND_FRAME_SIZE);
 }
 
 bool sndInit() {
@@ -60,7 +61,7 @@ bool sndInit() {
 
     // Initialize audio buffer and fill it with zeros
     sndData = new Sound::Frame[SND_FRAMES];
-    memset(sndData, 0, SND_FRAMES * sizeof(Sound::Frame));
+    memset(sndData, 0, SND_FRAMES * SND_FRAME_SIZE);
 
     SDL_PauseAudioDevice(sdl_audiodev,0);
 
@@ -102,6 +103,10 @@ void osJoyVibrate(int index, float L, float R) {
     // TODO
 }
 
+void osToggleVR(bool enable) {
+    // TODO
+}
+
 bool isKeyPressed (SDL_Scancode scancode) {
     const Uint8 *state = SDL_GetKeyboardState(NULL);
     if (state[scancode]) {