Mix together the barley flour, white flour, salt, bicarbonate of soda and cream of tartar. Stir in the buttermilk to make a firm dough. Shape into a round cake one inch thick, and cook on a very hot griddle, hotplate or heavy frying pan. When cooked on the underside, turn over and cook the second side. This may also be baked at 475°F, 240°C, gas mark 9 for twenty minutes without turning.