diff --git a/www/shaders/segfault.glsl b/www/shaders/segfault.glsl
index 78e9766..a90bf55 100644
--- a/www/shaders/segfault.glsl
+++ b/www/shaders/segfault.glsl
@@ -4,12 +4,15 @@
  * View this shader on shadertoy: https://www.shadertoy.com/view/t3tSRj#
  */
 
-#ifdef GL_ES
-precision highp float;
+// is highp wasteful for this shader?
+#ifdef GL_FRAGMENT_PRECISION_HIGH
+  precision highp float;
+#else
+  precision mediump float;
 #endif
 
-uniform float uTime;
-uniform vec2 uResolution;
+uniform float u_time;
+uniform vec2 u_resolution;
 
 /* ==== Text Colouring  ==== */
 #define PHOSPHOR_COL vec4(1, 1., 1., 1.)
@@ -151,9 +154,9 @@ float roundLine(vec2 p, vec2 a, vec2 b) {
 	b -= a + vec2(1.0,0.);
 	p -= a;
     float f = length(p-clamp(dot(p,b)/dot(b,b),0.0,1.0)*b);
-	if (uResolution.y < 320.) // attempt to get rid of aliasing on small resolution
+	if (u_resolution.y < 320.) // attempt to get rid of aliasing on small resolution
 		return smoothstep(1.0, 0.9, f);    
-    else if (uResolution.y < 720.)
+    else if (u_resolution.y < 720.)
 		return smoothstep(0.75, 0.5, f);    
 	else
 		return smoothstep(1., 0., f);    
@@ -301,7 +304,7 @@ float vt220Font(vec2 p, float c) {
 //     https://www.shadertoy.com/view/MsdGWn
 //
 float textLines(vec2 uvG) {
-    float wt = 5. * (uTime + 0.5*sin(uTime*1.4) + 0.2*sin(uTime*2.9)); // wobbly time
+    float wt = 5. * (u_time + 0.5*sin(u_time*1.4) + 0.2*sin(u_time*2.9)); // wobbly time
     vec2 uvGt = uvG + vec2(0., floor(wt));
     float ll = rand(vec2(uvGt.y, - 1.)) * ROWCOLS.x; // line length
     
@@ -346,33 +349,22 @@ float smokeNoise(vec3 v) {
     return fbm5(v) / 2. + 0.5;
 }
 
-// ===================================================================
-// Graphical Styling / Effects
-// 
-float bloom(vec2 uv2) {
-    // TODO
-    c += (textureLod(iChannel0, uvC, 3.) + 
-          textureLod(iChannel0, uvC, 4.) + 
-          textureLod(iChannel0, uvC, 5.))
-        * smoothstep(0., -SMOOTH*20., stdRS(uvC, -0.02)) * 0.5;
-}
-
 void main() {       
-   	vec2 uv = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y);
-   	vec2 uvT = ROWCOLS * FONT_SIZE * uv / uResolution.xy;
-   	vec2 uvG = floor(ROWCOLS * uv / uResolution.xy);
-    vec2 uvC = gl_FragCoord.xy / uResolution;
+   	vec2 uv = vec2(gl_FragCoord.x, u_resolution.y - gl_FragCoord.y);
+   	vec2 uvT = ROWCOLS * FONT_SIZE * uv / u_resolution.xy;
+   	vec2 uvG = floor(ROWCOLS * uv / u_resolution.xy);
+    vec2 uvC = gl_FragCoord.xy / u_resolution.xy;
         
-    vec2 uvNoise = uvC;
+    vec2 uvNoise = gl_FragCoord.xy / u_resolution.xy;
     uvNoise = ceil(uvNoise * ROWCOLS) / ROWCOLS;
     
     float val;
-    if (uTime < 2.0)
+    if (u_time < 2.0)
         val = textLines(uvG);
-    else if (uTime < 2.3)
-        val = rand(uvG * uTime) * 17.;
+    else if (u_time < 2.3)
+        val = rand(uvG * u_time) * 17.;
     else {
-        float noise = smokeNoise(vec3(uvNoise * noiseScale, uTime * noiseTimeScale));
+        float noise = smokeNoise(vec3(uvNoise * noiseScale, u_time * noiseTimeScale));
         // Noise is fed through a sigmoid function, then quantised to integer range 0-17
         val = (exp(noise) / 2.71828);  // increase contrast (normalised 0.0 - 1.0)
         val = 1.0 / val;