how to display long lists

Hello,
 
I have written a program that produces internally large lists of terms.
During debugging these lists are not displayed completely, but cut in
the tracer.
 
So I write them down into a file:    
    ...,
    open("debug.txt", append, S),
    write ( S, "comment " ),writeln (S, List ),
    close( S ),...
 
unformtunatelly with the same effect.
 
Is there a way to  obtain the complete list?
Thanks and best wishes
 
Cornelius