diff --git a/README.md b/README.md
index 9717f9d..2bdd10b 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,11 @@ OpenWebRX
 
 OpenWebRX is a multi-user SDR receiver software with a web interface.
 
-![OpenWebRX](/screenshot.png?raw=true)
+![OpenWebRX](http://blog.sdr.hu/images/screenshot.png)
+
+Its 3D waterfall display looks like this:
+
+![OpenWebRX 3D waterfall](http://blog.sdr.hu/images/screenshot-3d.gif)
 
 It has the following features:
 
@@ -28,13 +32,16 @@ It has the following features:
 - OpenWebRX now supports URLs like: `http://localhost:8073/#freq=145555000,mod=usb`
 - UI improvements were made, thanks to John Seamons and Gnoxter.
 
-> When upgrading OpenWebRX, please make sure that you also upgrade *csdr*, and install the new dependency, *ncat*!
+**News (2017-05-30)**
+- OpenWebRX now has a BPSK31 demodulator and a 3D waterfall display.
+
+> When upgrading OpenWebRX, please make sure that you also upgrade *csdr*!
 
 ## OpenWebRX servers on SDR.hu
 
 [SDR.hu](http://sdr.hu) is a site which lists the active, public OpenWebRX servers. Your receiver [can also be part of it](http://sdr.hu/openwebrx), if you want.
 
-![sdr.hu](/screenshot-sdrhu.png?raw=true)
+![sdr.hu](http://blog.sdr.hu/images/screenshot-sdrhu.png)
 
 ## Setup
 
diff --git a/csdr.py b/csdr.py
index dac7cdc..f63f77b 100755
--- a/csdr.py
+++ b/csdr.py
@@ -300,9 +300,9 @@ class dsp:
         return self.ddc_transition_bw_rate*(self.if_samp_rate()/float(self.samp_rate))
 
     def try_create_pipes(self, pipe_names, command_base):
-        print "try_create_pipes"
+        # print "try_create_pipes"
         for pipe_name in pipe_names:
-            print "\t"+pipe_name
+            # print "\t"+pipe_name
             if "{"+pipe_name+"}" in command_base:
                 setattr(self, pipe_name, self.pipe_base_path+pipe_name)
                 self.mkfifo(getattr(self, pipe_name))
diff --git a/htdocs/openwebrx.js b/htdocs/openwebrx.js
index eef9409..10629dd 100644
--- a/htdocs/openwebrx.js
+++ b/htdocs/openwebrx.js
@@ -2024,6 +2024,7 @@ function mathbox_init()
       controls: { klass: THREE.OrbitControls },
     });
     three = mathbox.three;
+    if(typeof three == "undefined") divlog("3D waterfall cannot be initialized because WebGL is not supported in your browser.", true);
 
     three.renderer.setClearColor(new THREE.Color(0x808080), 1.0);
 	mathbox_container.appendChild((mathbox_element=three.renderer.domElement));
@@ -2715,7 +2716,10 @@ function secondary_demod_waterfall_set_zoom(low_cut, high_cut)
     if(!secondary_demod || !secondary_demod_canvases_initialized) return;
     if(low_cut<0 && high_cut<0)
     {
-        [low_cut, high_cut] = [-high_cut, -low_cut];
+        var hctmp = high_cut;
+        var lctmp = low_cut;
+        low_cut = -hctmp;
+        low_cut = -lctmp;
     }
     else if(low_cut<0 && high_cut>0)
     {
diff --git a/screenshot-sdrhu.png b/screenshot-sdrhu.png
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diff --git a/screenshot.png b/screenshot.png
deleted file mode 100644
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