FileStream.WriteByte
using System; using System.IO; class WriteToFile { public static void Main(string[] args) { FileStream fout; try { fout = new FileStream("test.txt", FileMode.Create); } catch(IOException exc) { Console.WriteLine(exc.Message + "\nError Opening Output File"); return; } // Write the alphabet to the file. try { for(char c = 'A'; c <= 'Z'; c++) fout.WriteByte((byte) c); } catch(IOException exc) { Console.WriteLine(exc.Message + "File Error"); } fout.Close(); } }