If you hold down <kbd>GRPH</kbd> + <kbd>SHIFT</kbd> and type * <kbd>U</kbd><kbd>I</kbd><kbd>O</kbd> * <kbd>J</kbd><kbd>K</kbd><kbd>L</kbd> * <kbd>M</kbd><kbd><</kbd><kbd>></kbd> you'll see line drawing characters you can use to draw the grid for the game in Tandy 200 mode.