public byte[] slave1_status_code = new byte[256];

private void StatusToolStripMenuItem_Click(object sender, EventArgs e)
    Form4 ff4 = new Form4();
    ff4.Show();
}


public Form4()
{
    InitializeComponent();
    while (1<2)
    {
        string parsed="";
        for(int i = 0; i < 255; i++)
        {
            parsed += "Slave ";
            parsed += i;
            parsed += " status - ";
            //parsed +=
        }
    this.richTextBox1.Text = parsed;
}