diff --git a/src/gui/osc.cpp b/src/gui/osc.cpp
index 906e02e02..8f5104930 100644
--- a/src/gui/osc.cpp
+++ b/src/gui/osc.cpp
@@ -319,6 +319,7 @@ void FurnaceGUI::drawOsc() {
           _do.color=isClipping?uiColors[GUI_COLOR_OSC_WAVE_PEAK]:uiColors[GUI_COLOR_OSC_WAVE];
 
           dl->AddCallback(_drawOsc,&_do);
+          dl->AddCallback(ImDrawCallback_ResetRenderState,NULL);
         } else {
           for (int ch=0; ch<e->getAudioDescGot().outChans; ch++) {
             for (int i=0; i<oscWidth-24; i++) {
diff --git a/src/gui/render/renderGL.cpp b/src/gui/render/renderGL.cpp
index 86169069a..b4c60fcd0 100644
--- a/src/gui/render/renderGL.cpp
+++ b/src/gui/render/renderGL.cpp
@@ -114,7 +114,8 @@ const char* sh_oscRender_srcF=
   "  float valmin = min(min(val1,val2),val3);\n"
   "  float vald = abs(valmax-valmin);\n"
   "  float alpha = 1.0-abs(uv.y-val2)/max(tresh.y,vald);\n"
-  "  gl_FragColor = vec4(uColor.xyz,uColor.w*alpha);\n"
+  "  //gl_FragColor = vec4(uColor.xyz,uColor.w*alpha);\n"
+  "  gl_FragColor = vec4(clamp(0.5+val2*0.5,0.0,1.0),0.0,0.0,1.0);\n"
   "}\n";
 #else
 const char* sh_wipe_srcV=
@@ -377,13 +378,24 @@ void FurnaceGUIRenderGL::drawOsc(float* data, size_t len, ImVec2 pos0, ImVec2 po
   if (!furUniform2f) return;
   if (!furUniform1i) return;
 
-  if (furBufferData) return;
-
-  logV("%d",oscVertexBuf);
   if (len>2048) len=2048;
 
   memcpy(oscData,data,len*sizeof(float));
 
+  int lastArrayBuf=0;
+  int lastElemArrayBuf=0;
+  int lastTex=0;
+  int lastProgram=0;
+  int lastActiveTex=0;
+  C(glGetIntegerv(GL_ACTIVE_TEXTURE,&lastActiveTex));
+  C(furActiveTexture(GL_TEXTURE0));
+
+#ifdef USE_GLES
+  C(glGetIntegerv(GL_TEXTURE_BINDING_2D,&lastTex));
+#else
+  C(glGetIntegerv(GL_TEXTURE_BINDING_1D,&lastTex));
+#endif
+
 #ifdef USE_GLES
   C(glBindTexture(GL_TEXTURE_2D,oscDataTex));
   C(glTexImage2D(GL_TEXTURE_2D,0,GL_RED_EXT,2048,1,0,GL_RED_EXT,GL_FLOAT,oscData));
@@ -392,13 +404,13 @@ void FurnaceGUIRenderGL::drawOsc(float* data, size_t len, ImVec2 pos0, ImVec2 po
   C(glTexImage1D(GL_TEXTURE_1D,0,GL_RED,2048,0,GL_RED,GL_FLOAT,oscData));
 #endif
 
-  C(glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA));
-  C(glEnable(GL_BLEND));
+  //C(glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA));
+  //C(glEnable(GL_BLEND));
 
   pos0.x=(2.0f*pos0.x/canvasSize.x)-1.0f;
-  pos0.y=(2.0f*pos0.y/canvasSize.y)-1.0f;
+  pos0.y=1.0f-(2.0f*pos0.y/canvasSize.y);
   pos1.x=(2.0f*pos1.x/canvasSize.x)-1.0f;
-  pos1.y=(2.0f*pos1.y/canvasSize.y)-1.0f;
+  pos1.y=1.0f-(2.0f*pos1.y/canvasSize.y);
 
   oscVertex[0][0]=pos0.x;
   oscVertex[0][1]=pos1.y;
@@ -406,36 +418,51 @@ void FurnaceGUIRenderGL::drawOsc(float* data, size_t len, ImVec2 pos0, ImVec2 po
   oscVertex[0][3]=1.0f;
   oscVertex[1][0]=pos1.x;
   oscVertex[1][1]=pos1.y;
-  oscVertex[1][2]=1.0f;
+  oscVertex[1][2]=(float)len;
   oscVertex[1][3]=1.0f;
   oscVertex[2][0]=pos0.x;
   oscVertex[2][1]=pos0.y;
   oscVertex[2][2]=0.0f;
-  oscVertex[2][3]=0.0f;
+  oscVertex[2][3]=-1.0f;
   oscVertex[3][0]=pos1.x;
   oscVertex[3][1]=pos0.y;
-  oscVertex[3][2]=1.0f;
-  oscVertex[3][3]=0.0f;
+  oscVertex[3][2]=(float)len;
+  oscVertex[3][3]=-1.0f;
+
+  C(glGetIntegerv(GL_ARRAY_BUFFER_BINDING,&lastArrayBuf));
+  C(glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING,&lastElemArrayBuf));
 
   C(furBindBuffer(GL_ARRAY_BUFFER,oscVertexBuf));
+  C(furBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0));
   C(furBufferData(GL_ARRAY_BUFFER,sizeof(oscVertex),oscVertex,GL_STATIC_DRAW));
   C(furVertexAttribPointer(0,2,GL_FLOAT,GL_FALSE,4*sizeof(float),NULL));
-  //C(furVertexAttribPointer(1,2,GL_FLOAT,GL_FALSE,4*sizeof(float),(void*)(2*sizeof(float))));
+  C(furVertexAttribPointer(1,2,GL_FLOAT,GL_FALSE,4*sizeof(float),(void*)(2*sizeof(float))));
   C(furEnableVertexAttribArray(0));
-  //C(furEnableVertexAttribArray(1));
-  C(furActiveTexture(GL_TEXTURE0));
-  C(glBindTexture(GL_TEXTURE_2D,oscDataTex));
+  C(furEnableVertexAttribArray(1));
+
+  C(glGetIntegerv(GL_CURRENT_PROGRAM,&lastProgram));
 
   C(furUseProgram(sh_oscRender_program));
   C(furUniform4fv(sh_oscRender_uColor,1,(float*)&color));
   C(furUniform1f(sh_oscRender_uLineWidth,lineWidth));
-  C(furUniform2f(sh_oscRender_uResolution,1.0f,1.0f));
+  C(furUniform2f(sh_oscRender_uResolution,2048.0f,1.0f));
   C(furUniform1i(sh_oscRender_oscVal,0));
 
   C(glDrawArrays(GL_TRIANGLE_STRIP,0,4));
-  //C(furDisableVertexAttribArray(1));
-  C(furUseProgram(0));
-  C(glBindTexture(GL_TEXTURE_2D,0));
+  C(furDisableVertexAttribArray(1));
+
+  // restore state
+  C(furUseProgram(lastProgram));
+
+  C(furBindBuffer(GL_ARRAY_BUFFER,lastArrayBuf));
+  C(furBindBuffer(GL_ELEMENT_ARRAY_BUFFER,lastElemArrayBuf));
+
+#ifdef USE_GLES
+  C(glBindTexture(GL_TEXTURE_2D,lastTex));
+#else
+  C(glBindTexture(GL_TEXTURE_1D,lastTex));
+#endif
+  C(furActiveTexture(lastActiveTex));
 }
 
 void FurnaceGUIRenderGL::present() {
@@ -558,6 +585,7 @@ bool FurnaceGUIRenderGL::init(SDL_Window* win) {
   }
 
   C(furGenBuffers(1,&quadBuf));
+  C(furGenBuffers(1,&oscVertexBuf));
   return true;
 }