So I did some research on the Net (meaning Google ;)) and found HandyBoard. It can do exactly what I need and it's very simple to program. HandyBoard runs special system called Interactive C which allows you to connect to the microcontroller through the serial interface and execute C-language commands in real-time right on the board. It's incredible! Simply connect your robot to a computer and using one simple command it's possible to control all motors, read inputs, send data to outputs, control display and more. It works almost like a normal unix shell. I was impressed.

The biggest challenge was getting all the electronic parts. I couldn't find some parts with exactly the same parameters as stated in the HandyBoard documentation, but it's life... Fortunately it was easy to find list of equivalent parts so I managed to buy everything.

Originally I wanted to make the printed circuit board (PCB) by myself, but I realized that its drawing was only available as a set of GIF images and redraw them to the computer would have taken me at least a week or two I quickly decided to order over the Internet from a manufacturer in California. It turned out that it was much cheaper than if I let it manufacture here in Czech Republic. And I must say that its quality was really perfect. Non-soldering mack, metalic holes, printing on top, simply wonderful.

After about three days (I couldn't find a resistance net with 10 pins) I had finished the main PCB as well as the interface board. Everything went smooth.