+ * | | | | | | | |
+ * | | | | scrollwin | | | |
+ * | | | | +---------------------------------------------+ | | | |
+ * | | | | | Internal memory window | | | | |
+ * | | | | +---------------------------------------------+ | | | |
+ * | | | | | | | |
+ * | | | +-----------------------***-------------------------| | | |
+ * | | | | | | | |
+ * | | | | scrollwin | | | |
+ * | | | | +---------------------------------------------+ | | | |
+ * | | | | | External memory window | | | | |
+ * | | | | +---------------------------------------------+ | | | |
+ * | | | | | | | |