--- /dev/null
+/*
+ * (C) Copyright 2000
+ * Murray Jensen <Murray.Jensen@csiro.au>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <termios.h>
+
+#define SERIAL_ERROR -1 /* General error, see errno for details */
+#define SERIAL_TIMEOUT -2
+#define SERIAL_EOF -3
+
+extern speed_t cvtspeed(char *);
+extern int serialopen(char *, speed_t);
+extern int serialreadchar(int, int);
+extern int serialwrite(int, char *, int);
+extern int serialclose(int);