diff --git a/audio-worklet/src/jsMain/kotlin/nl/astraeus/vst/chip/ChipProcessor.kt b/audio-worklet/src/jsMain/kotlin/nl/astraeus/vst/chip/ChipProcessor.kt
index a76f2a8..a65de46 100644
--- a/audio-worklet/src/jsMain/kotlin/nl/astraeus/vst/chip/ChipProcessor.kt
+++ b/audio-worklet/src/jsMain/kotlin/nl/astraeus/vst/chip/ChipProcessor.kt
@@ -59,6 +59,7 @@ enum class Waveform {
 @ExperimentalJsExport
 @JsExport
 class VstChipProcessor : AudioWorkletProcessor() {
+  var midiChannel = 0
   val notes = Array(POLYPHONICS) {
     PlayingNote(
       0
@@ -78,41 +79,58 @@ class VstChipProcessor : AudioWorkletProcessor() {
   }
 
   private fun handleMessage(message: MessageEvent) {
-    //console.log("VstChipProcessor: Received message", message)
+    console.log("VstChipProcessor: Received message:", message.data)
 
     val data = message.data
 
-    when (data) {
-      "test_on" -> {
-        playMidi(Int32Array(arrayOf(0x90, 60, 64)))
-
-      }
-      "test_off" -> {
-        playMidi(Int32Array(arrayOf(0x90, 60, 0)))
-      }
-      is String -> {
-      }
-      is ArrayBuffer -> {
-      }
-      is Uint8Array -> {
-        val data32 = Int32Array(data.length)
-        for (i in 0 until data.length) {
-          data32[i] = (data[i].toInt() and 0xff)
+    try {
+      when (data) {
+        is String -> {
+          if (data.startsWith("set_channel")) {
+            val parts = data.split('\n')
+            if (parts.size == 2) {
+              midiChannel = parts[1].toInt()
+              println("Setting channel: $midiChannel")
+            }
+          }
         }
-        playMidi(data32)
+
+        is Uint8Array -> {
+          val data32 = Int32Array(data.length)
+          for (i in 0 until data.length) {
+            data32[i] = (data[i].toInt() and 0xff)
+          }
+          playMidi(data32)
+        }
+
+        is Int32Array -> {
+          playMidi(data)
+        }
+
+        else ->
+          console.error("Don't kow how to handle message", message)
       }
-      is Int32Array -> {
-        playMidi(data)
-      }
-      else ->
-        console.error("Don't kow how to handle message", message)
+    } catch(e: Exception) {
+      console.log(e.message, e)
     }
   }
 
   private fun playMidi(bytes: Int32Array) {
+    console.log("playMidi", bytes)
     if (bytes.length > 0) {
+      var cmdByte = bytes[0]
+      val channelCmd = ((cmdByte shr 4) and 0xf) in 0x8 .. 0xe
+      val channel = cmdByte and 0xf
+      println("Channel cmd: $channelCmd")
+      if (channelCmd && channel != midiChannel) {
+        console.log("Wrong channel", midiChannel, bytes)
+        return
+      }
+
+      cmdByte = cmdByte and 0xf0
+
       //console.log("Received", bytes)
-      when(bytes[0]) {
+      when(cmdByte) {
         0x90 -> {
           if (bytes.length == 3) {
             val note = bytes[1]
diff --git a/build.gradle.kts b/build.gradle.kts
index 1754011..85d618d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,7 +6,6 @@ buildscript {
 
 plugins {
     kotlin("multiplatform")
-    kotlin("plugin.serialization")
     id("maven-publish")
     application
 }
diff --git a/settings.common.gradle.kts b/settings.common.gradle.kts
index 08e8c93..4230eaf 100644
--- a/settings.common.gradle.kts
+++ b/settings.common.gradle.kts
@@ -1,7 +1,6 @@
 pluginManagement {
   plugins {
     kotlin("multiplatform") version "2.0.0"
-    kotlin("plugin.serialization") version "2.0.0"
     id("org.gradle.toolchains.foojay-resolver-convention") version "0.5.0"
   }
   repositories {
diff --git a/src/jsMain/kotlin/nl/astraeus/vst/chip/audio/AudioModule.kt b/src/jsMain/kotlin/nl/astraeus/vst/chip/audio/AudioModule.kt
index 82f582a..f5e835a 100644
--- a/src/jsMain/kotlin/nl/astraeus/vst/chip/audio/AudioModule.kt
+++ b/src/jsMain/kotlin/nl/astraeus/vst/chip/audio/AudioModule.kt
@@ -54,6 +54,9 @@ abstract class AudioNode(
   abstract fun onMessage(message: MessageEvent)
 
   open fun postMessage(msg: Any) {
+    if (port == null) {
+      console.log("postMessage port is NULL!")
+    }
     port?.postMessage(msg)
   }
 
diff --git a/src/jsMain/kotlin/nl/astraeus/vst/chip/view/MainView.kt b/src/jsMain/kotlin/nl/astraeus/vst/chip/view/MainView.kt
index 523bed5..5809c74 100644
--- a/src/jsMain/kotlin/nl/astraeus/vst/chip/view/MainView.kt
+++ b/src/jsMain/kotlin/nl/astraeus/vst/chip/view/MainView.kt
@@ -13,6 +13,7 @@ import kotlinx.html.h1
 import kotlinx.html.input
 import kotlinx.html.js.onChangeFunction
 import kotlinx.html.js.onClickFunction
+import kotlinx.html.js.onInputFunction
 import kotlinx.html.option
 import kotlinx.html.select
 import kotlinx.html.span
@@ -111,9 +112,11 @@ object MainView : Komponent() {
           input {
             type = InputType.number
             value = Midi.inputChannel.toString()
-            onChangeFunction = { event ->
+            onInputFunction = { event ->
               val target = event.target as HTMLInputElement
               Midi.inputChannel = target.value.toInt()
+              println("onInput channel: ${Midi.inputChannel}")
+              VstChipWorklet.postMessage("set_channel\n${Midi.inputChannel}")
             }
           }
         }
@@ -155,7 +158,7 @@ object MainView : Komponent() {
           input {
             type = InputType.number
             value = Midi.outputChannel.toString()
-            onChangeFunction = { event ->
+            onInputFunction = { event ->
               val target = event.target as HTMLInputElement
               Midi.outputChannel = target.value.toInt()
             }
@@ -230,6 +233,8 @@ object MainView : Komponent() {
           margin(1.rem)
           padding(1.rem)
           backgroundColor(Css.currentStyle.buttonBackgroundColor)
+          borderColor(Css.currentStyle.buttonBorderColor)
+          borderWidth(Css.currentStyle.buttonBorderWidth)
           color(Css.currentStyle.mainFontColor)
 
           hover {
diff --git a/src/jsMain/kotlin/nl/astraeus/vst/chip/view/css/Css.kt b/src/jsMain/kotlin/nl/astraeus/vst/chip/view/css/Css.kt
index 8d3ab64..40b9709 100644
--- a/src/jsMain/kotlin/nl/astraeus/vst/chip/view/css/Css.kt
+++ b/src/jsMain/kotlin/nl/astraeus/vst/chip/view/css/Css.kt
@@ -13,7 +13,7 @@ class StyleDefinition(
   val inputBackgroundColor : Color = mainBackgroundColor.lighten(15),
   val buttonBackgroundColor : Color = mainBackgroundColor.lighten(15),
   val buttonBorderColor : Color = mainFontColor.changeAlpha(0.25),
-  val buttonBorderWidth : Measurement = 2.px,
+  val buttonBorderWidth : Measurement = 1.px,
 )
 
 object NoTextSelectCls : CssName("no-text-select")