diff --git a/dosfstools/src/io.h b/dosfstools/src/io.h
new file mode 100644
index 0000000..2db4ea7
--- /dev/null
+++ b/dosfstools/src/io.h
@@ -0,0 +1,70 @@
+/* io.h - Virtual disk input/output
+
+   Copyright (C) 1993 Werner Almesberger <werner.almesberger@lrc.di.epfl.ch>
+   Copyright (C) 1998 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+   On Debian systems, the complete text of the GNU General Public License
+   can be found in /usr/share/common-licenses/GPL-3 file.
+*/
+
+/* FAT32, VFAT, Atari format support, and various fixes additions May 1998
+ * by Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> */
+
+#ifndef _IO_H
+#define _IO_H
+
+#include <sys/types.h>		/* for loff_t */
+
+loff_t llseek(int fd, loff_t offset, int whence);
+
+/* lseek() analogue for large offsets. */
+
+void fs_open(char *path, int rw);
+
+/* Opens the file system PATH. If RW is zero, the file system is opened
+   read-only, otherwise, it is opened read-write. */
+
+void fs_read(loff_t pos, int size, void *data);
+
+/* Reads SIZE bytes starting at POS into DATA. Performs all applicable
+   changes. */
+
+int fs_test(loff_t pos, int size);
+
+/* Returns a non-zero integer if SIZE bytes starting at POS can be read without
+   errors. Otherwise, it returns zero. */
+
+void fs_write(loff_t pos, int size, void *data);
+
+/* If write_immed is non-zero, SIZE bytes are written from DATA to the disk,
+   starting at POS. If write_immed is zero, the change is added to a list in
+   memory. */
+
+int fs_close(int write);
+
+/* Closes the file system, performs all pending changes if WRITE is non-zero
+   and removes the list of changes. Returns a non-zero integer if the file
+   system has been changed since the last fs_open, zero otherwise. */
+
+int fs_changed(void);
+
+/* Determines whether the file system has changed. See fs_close. */
+
+extern unsigned device_no;
+
+/* Major number of device (0 if file) and size (in 512 byte sectors) */
+
+#endif