import javax.swing.*;
import java.awt.*;

class OutputWindow {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Output");
        frame.setLocation(100,100);

        JTextArea textArea = new JTextArea();
        textArea.setEditable(false);
        textArea.setPreferredSize(new Dimension(50,500));

        frame.add(textArea);
        frame.pack();
        frame.setVisible(true);

        textArea.setText("Testing...\n");
        textArea.append("1... 2... 3...");
    }
}