diff --git a/simulator/main.cpp b/simulator/main.cpp
index c8eae31..c5ae767 100644
--- a/simulator/main.cpp
+++ b/simulator/main.cpp
@@ -19,7 +19,7 @@
 #endif
 
 // --- Configuration ---
-const uint32_t SAMPLE_RATE = 44100;
+const uint32_t SAMPLE_RATE = 44100 / 4;
 const uint32_t CHANNELS = 1; // Mono
 const int CELL_SIZE = 60;
 const int GRID_PANEL_WIDTH = 12 * CELL_SIZE; // 720
@@ -46,6 +46,7 @@ Uint32 auto_melody_next_event_time = 0;
 const int c_major_scale[] = {0, 2, 4, 5, 7, 9, 11, 12}; // Semitones from root
 int current_preset = 0;
 int current_patch_slot = 0; // 0-7
+SynthEngine::GridCell clipboardCell;
 
 float note_to_freq(int octave, int semitone_offset);
 
@@ -165,7 +166,7 @@ void checkSerialInput(FILE* serialPort) {
         } else if (state == 1) { // Count
             elementCount = b;
             printf("Grid element count: %d\n", elementCount);
-            if (1 + elementCount * 5 + 1 > sizeof(buffer)) {
+            if ((size_t)(1 + elementCount * 5 + 1) > sizeof(buffer)) {
                 state = 0;
                 bufferIdx = 0;
                 printf("ERROR: Grid too large (count: %d)\n", elementCount);
@@ -1363,6 +1364,39 @@ int main(int argc, char* argv[]) {
                             engine.setGate(true);
                         }
                     }
+
+                    // Copy & Paste
+                    if (e.key.keysym.scancode == SDL_SCANCODE_C) {
+                        int mx, my;
+                        SDL_GetMouseState(&mx, &my);
+                        if (mx < GRID_PANEL_WIDTH) {
+                            int gx = mx / CELL_SIZE;
+                            int gy = my / CELL_SIZE;
+                            if (gx >= 0 && gx < SynthEngine::GRID_W && gy >= 0 && gy < SynthEngine::GRID_H) {
+                                SynthLockGuard<SynthMutex> lock(engine.gridMutex);
+                                clipboardCell = engine.grid[gx][gy];
+                            }
+                        }
+                    } else if (e.key.keysym.scancode == SDL_SCANCODE_V) {
+                        int mx, my;
+                        SDL_GetMouseState(&mx, &my);
+                        if (mx < GRID_PANEL_WIDTH) {
+                            int gx = mx / CELL_SIZE;
+                            int gy = my / CELL_SIZE;
+                            if (gx >= 0 && gx < SynthEngine::GRID_W && gy >= 0 && gy < SynthEngine::GRID_H) {
+                                {
+                                    SynthLockGuard<SynthMutex> lock(engine.gridMutex);
+                                    engine.grid[gx][gy] = clipboardCell;
+                                    // Reset runtime state
+                                    engine.grid[gx][gy].value = 0;
+                                    engine.grid[gx][gy].next_value = 0;
+                                    engine.grid[gx][gy].phase = 0;
+                                    engine.grid[gx][gy].phase_accumulator = 0;
+                                }
+                                engine.rebuildProcessingOrder();
+                            }
+                        }
+                    }
                 }
             } else if (e.type == SDL_MOUSEBUTTONUP) {
                 if (exportButtonPressed) {
@@ -1567,6 +1601,12 @@ int main(int argc, char* argv[]) {
         snprintf(slotBuf, sizeof(slotBuf), "SLOT %d", current_patch_slot);
         drawString(renderer, 380, 600, 12, slotBuf);
 
+        // Buffer Preview
+        drawString(renderer, 50, 560, 12, "BUFFER");
+        drawGridCell(renderer, 50, 580, CELL_SIZE, clipboardCell);
+        drawString(renderer, 50, 580 + CELL_SIZE + 10, 12, "C-COPY");
+        drawString(renderer, 50, 580 + CELL_SIZE + 30, 12, "V-PASTE");
+
         drawButton(renderer, 270, 535, 80, 30, "SAVE", saveButtonPressed);
         drawButton(renderer, 450, 535, 80, 30, "LOAD", loadButtonPressed);
 
diff --git a/synth_engine.cpp b/synth_engine.cpp
index 2e0c5ea..1c528aa 100644
--- a/synth_engine.cpp
+++ b/synth_engine.cpp
@@ -55,8 +55,8 @@ SynthEngine::SynthEngine(uint32_t sampleRate)
       _increment(0),
       _volume(0.5f),
       _waveform(SAWTOOTH),
-      _isGateOpen(false),
       _freqToPhaseInc(0.0f),
+      _isGateOpen(false),
       _rngState(12345)
 {
     fill_wave_tables();