This paper presents a tool for automatic layout of bidimensional processor arrays. The general topology of such structures consists of a processor cells array and interconnections restricted to nearest neighbors. Automatic layout of such structures can be viewed as processor cells tiling with regular routing between cells. The Madmacs design system is proposed as a tool to generate such structures. Madmacs is a complete graphics layout editor that features logical and coordinate free cursor movements. Furthermore, Madmacs provides a classical but interactive macro-command mechanism. This mechanism is particularly efficient for repetitive tasks like tiling and regular routing. Finally, Madmacs is tightly coupled to a Lisp interpreter. Each Madmacs command has a functional form in the LISP language. As the interpreter evaluates an editor command function, it calls Madmacs which executes the associated command. The LISP language is also available to develop the skeleton of generators. With Madmacs coordinate free cursor movements, the designer is not concerned with the exact sizes of the manipulated objects and so can develop re-usable code. Finally, a macro command can be saved as a new LISP function, and incorporated into a generator. The combined language and interactive approach allows one to obtain fast definitions of generators.