diff --git a/testback.c b/testback.c
new file mode 100644
index 00000000..fddfb84e
--- /dev/null
+++ b/testback.c
@@ -0,0 +1,83 @@
+/* $Id: testback.c,v 1.1.2.1 1999/03/07 23:23:38 ben Exp $ */
+/*
+ * Copyright (c) 1999 Simon Tatham
+ * Copyright (c) 1999 Ben Harris
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ * 
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/* PuTTY test backends */
+
+#include <stdlib.h>
+
+#include "putty.h"
+
+static char *null_init(char *, int, char **);
+static int null_msg(void);
+static void null_send(char *, int);
+static void loop_send(*char *, int);
+static void null_size(void);
+static void null_special(Telnet_Special);
+
+Backend null_backend = {
+    null_init, null_msg, null_send, null_size, null_special
+};
+
+Backend loop_backend = {
+    null_init, null_msg, loop_send, null_size, null_special
+};
+
+static char *null_init(char *host, int port, char **realhost) {
+
+    return NULL;
+}
+
+static int null_msg(void) {
+
+    return 1;
+}
+
+static void null_send(char *buf, int len) {
+
+}
+
+static void lo_send (char *buf, int len) {
+    while (len--) {
+	int new_head = (inbuf_head + 1) & INBUF_MASK;
+	int c = (unsigned char) *buf;
+	if (new_head != inbuf_reap) {
+	    inbuf[inbuf_head] = *buf++;
+	    inbuf_head = new_head;
+	}
+    }
+}
+
+
+
+static void null_size(void) {
+
+}
+
+static void null_special(Telnet_Special code) {
+
+}