diff --git a/sys/input_to.h b/sys/input_to.h
new file mode 100644
index 0000000..f7f094f
--- /dev/null
+++ b/sys/input_to.h
@@ -0,0 +1,17 @@
+#ifndef LPC_INPUT_TO_H_
+#define LPC_INPUT_TO_H_
+
+/* Mode values recognized by the efun input_to() */
+
+#define INPUT_NOECHO         1  /* Don't echo the next line typed */
+#define INPUT_CHARMODE       2  /* Switch into/out of charmode */
+#define INPUT_PROMPT         4  /* Use a custom prompt */
+#define INPUT_NO_TELNET      8  /* Switch into/out of charmode on the driver
+                                 * side only.
+                                 */
+#define INPUT_APPEND        16  /* Append the input_to to the list of already
+                                 * pending input_to's.
+                                 */
+#define INPUT_IGNORE_BANG  128  /* Disallow the '!' escape */
+
+#endif /* LPC_INPUT_TO_H_ */