hi, To begin with you can write a small module that when loaded simply prints a string on to the screen,and another string when rmmoded. Then you can write a pseudo driver module that would treat a memory region in the RAM as a character device and then simulate the driver functionalities whenever you try to read/write the device(Memory).This would get you a feel of control flow. Then you can write a Serial port driver and test it with the help of minicom. Regards- Kaushal. Rocsys Technologies. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/