diff --git a/plugin/chassis.cpp b/plugin/chassis.cpp
index 3b9c4ae..7112499 100644
--- a/plugin/chassis.cpp
+++ b/plugin/chassis.cpp
@@ -69,11 +69,12 @@ void Chassis::noteOn(uint8_t note) {
     ic1.ram[0x3e] = note;
     ic1.noteOn();
 
+/*
     for (uint8_t i = 0x40; i < 0x4f; i++) {
         printf("%02x ", ic1.ram[i]);
     }
     printf("\n");
-
+*/
     s.keyon = true;
     for (i = 0; i < NUM_VOICES; i++) {
         vPtr++;
@@ -97,11 +98,12 @@ void Chassis::noteOff(uint8_t note) {
     ic1.ram[0x3e] = note;
     ic1.noteOn();
 
+/*
     for (uint8_t i = 0x40; i < 0x4f; i++) {
         printf("%02x ", ic1.ram[i]);
     }
     printf("\n");
-
+*/
     s.keyon = false;
     for (uint32_t i = 0; i < NUM_VOICES; i++) {
         if (s.voice[i].note == note && !s.voice[i].isFree()) {
@@ -126,6 +128,8 @@ void Chassis::doMidi(const MidiEvent *ev, uint32_t count, uint32_t timeLimit) {
         }
     }
     lastEvent = i;
+
+    ic1.voiceOn();
 }
 
 void Chassis::run(const float **, float **outputs, uint32_t frames, const MidiEvent *midiEvents, uint32_t midiEventCount) {
diff --git a/plugin/cpuboard.cpp b/plugin/cpuboard.cpp
index ccd712f..c6e355a 100644
--- a/plugin/cpuboard.cpp
+++ b/plugin/cpuboard.cpp
@@ -2,16 +2,77 @@
 
 #include <cstdio>
 
-void Assigner::noteOn() {
+void Assigner::resetVoices() {
+    // 0b81
+    for (uint16_t i = 0x80; i < 0x85; i++) {
+        ram[i + 8] = 0x80;  // 0b81 loop
+        ram[i] = i + 0x88;  // 0b8b loop
+    }
+    ram[0x86] = 0x88;  // 0b96
+}
 
+void Assigner::clearNotes() {
+    // 0b9e
+    // loop over ff30 to ff3d zeroing out the "played notes" bits
+    for (uint16_t hl = 0x30; hl < 0x3d; hl++) {
+        ram[hl] = 0;
+    }
+}
+
+void Assigner::voiceOn() {
+    // 01e0 which we fall through to after scanning the key matrix
+
+    b = 0x0d;       // bytes in scan table
+    hl = 0x3d;      // ff3d, top of "enabled" notes
+    de = 0x57;      // the key matrix is stored here
+    ram[0xd0] = 0;  // unsure
+
+h01eb:
+    a = ram[hl + 0x10];  // read MIDI bitmap
+    // 01ed
+    // LTI B, $03; LTI B, $0B
+    // I believe this selects only the key bitmap addresses from DE
+    // 1f3 jr 01f7
+    // 1f4 orax (DE) ; or in the bitmap at (DE) (keys pressed)
+
+    // 1f7
+    c = a;
+    a ^= ram[hl];  // XRAX (HL), compare with already pressed
+
+    if (a == 0) {
+        // 01fa SK Z
+    } else {
+        // 01fc CALF $0A18;
+        printf("new note change detected\n");
+    }
+
+    a = c;        // restore A
+    ram[hl] = a;  // store bitfield at $ff30
+
+    hl--;
+    if (b > 0) {
+        b--;
+        goto h01eb;
+    }
+
+    // 0203
+    if (ram[0xd0] != 0xff) {
+        // skip
+    } else {
+        // 0206 CALF $0b9e
+        clearNotes();
+    }
+}
+
+void Assigner::noteOn() {
     // called from serial interrupt handler
     // sets or clears a bit in the "MIDI Key pressed" bitfield
 
     // note that RAM addresses normally set to 0xff40 are reduced to 0x0040
-    
+
     // 06ca
     a = ram[0x3e];  // first byte is note value
-    c = 0x40;   // fake velocity
+    c = 0x40;       // fake velocity
 
     // bring note into range
     // 06cc
@@ -34,23 +95,22 @@ void Assigner::noteOn() {
     // 06e8 lxi hl,$0008; ldax (a+hl) for table of bits
     a = 1 << a;
     c = a;
-    hl = 0x0040;        // note bit flags
-    a = ram[hl + b];    // byte pointed to by upper part
-    a |= c;             // or in the bit value
-    ram[hl+b] = a;      // save it in RAM
-    
+    hl = 0x0040;      // note bit flags
+    a = ram[hl + b];  // byte pointed to by upper part
+    a |= c;           // or in the bit value
+    ram[hl + b] = a;  // save it in RAM
+
     // 06f4 mviw $003f, $01 expect two bytes; jre $064c return from interrupt
     return;
 
-    h06f9:    // note off
+h06f9:  // note off
 
     a = 0xff ^ (1 << a);
     c = a;
-    hl = 0x0040;        // note bit flags
-    a = ram[hl + b];    // byte pointed to by upper part
-    a &= c;             // mask off the bit
-    ram[hl+b] = a;      // save it in RAM    
+    hl = 0x0040;      // note bit flags
+    a = ram[hl + b];  // byte pointed to by upper part
+    a &= c;           // mask off the bit
+    ram[hl + b] = a;  // save it in RAM
 
     return;
-
 }
\ No newline at end of file
diff --git a/plugin/cpuboard.hpp b/plugin/cpuboard.hpp
index f5746f7..0a6d6dc 100644
--- a/plugin/cpuboard.hpp
+++ b/plugin/cpuboard.hpp
@@ -9,5 +9,8 @@ class Assigner {
     uint32_t bc, de, hl, ea = 0;
 
     void noteOn();
+    void voiceOn();
+    void resetVoices();
+    void clearNotes();
 
 };
\ No newline at end of file