diff --git a/Startcode/neuralNetworkTests.c b/Startcode/neuralNetworkTests.c
index 21ab370..efc1ab7 100644
--- a/Startcode/neuralNetworkTests.c
+++ b/Startcode/neuralNetworkTests.c
@@ -9,6 +9,39 @@
 static void prepareNeuralNetworkFile(const char *path, const NeuralNetwork nn)
 {
     // TODO
+    FILE *file = fopen(path, "wb");
+    if (file == NULL)
+    {
+        return;
+    }
+
+    const char *fileTag = "__info2_neural_network_file_format__";
+    fwrite(fileTag, sizeof(char), strlen(fileTag), file);
+
+    if (nn.numberOfLayers > 0)
+    {
+        fwrite(&nn.layers[0].weights.cols, sizeof(int), 1, file);
+        fwrite(&nn.layers[0].weights.rows, sizeof(int), 1, file);
+
+        for (unsigned int i = 0; i < nn.numberOfLayers; i++)
+        {
+            if (i > 0)
+            {
+                fwrite(&nn.layers[i].weights.rows, sizeof(int), 1, file);
+            }
+
+            fwrite(nn.layers[i].weights.buffer, sizeof(MatrixType),
+                   nn.layers[i].weights.rows * nn.layers[i].weights.cols, file);
+
+            fwrite(nn.layers[i].biases.buffer, sizeof(MatrixType),
+                   nn.layers[i].biases.rows * nn.layers[i].biases.cols, file);
+        }
+    }
+
+    int endDimension = 0;
+    fwrite(&endDimension, sizeof(int), 1, file);
+
+    fclose(file);
 }
 
 void test_loadModelReturnsCorrectNumberOfLayers(void)