diff --git a/neuralNetworkTests.c b/neuralNetworkTests.c
index d6c8322..272dde4 100644
--- a/neuralNetworkTests.c
+++ b/neuralNetworkTests.c
@@ -7,7 +7,45 @@
 
 static void prepareNeuralNetworkFile(const char *path, const NeuralNetwork nn)
 {
-   
+    FILE *f = fopen(path, "wb");
+    if (!f) return;
+
+    const char *tag = "__info2_neural_network_file_format__";
+    fwrite(tag, 1, strlen(tag), f);
+
+    if (nn.numberOfLayers == 0) {
+        fclose(f);
+        return;
+    }                                                               // Alle Tests prüfen 
+
+  
+    int input  = nn.layers[0].weights.cols;
+    int output = nn.layers[0].weights.rows;
+
+    fwrite(&input,  sizeof(int), 1, f);
+    fwrite(&output, sizeof(int), 1, f);
+
+    for (int i = 0; i < nn.numberOfLayers; i++)
+    {
+        const Layer *layer = &nn.layers[i];
+        int out = layer->weights.rows;
+        int in  = layer->weights.cols;
+
+        
+        fwrite(layer->weights.buffer, sizeof(MatrixType), out * in, f);
+
+        
+        fwrite(layer->biases.buffer, sizeof(MatrixType), out * 1, f);
+
+        
+        if (i + 1 < nn.numberOfLayers)
+        {
+            int nextOut = nn.layers[i + 1].weights.rows;
+            fwrite(&nextOut, sizeof(int), 1, f);
+        }
+    }
+
+    fclose(f);
 }
 
 void test_loadModelReturnsCorrectNumberOfLayers(void)