Mix tomatoes and salt. Let stand about 12 hours. Drain.
Heat vinegar, sugars and spices to a boil; add sliced onions and boil gently 5 minutes. Add the drained tomatoes and peppers; bring slowly to a boil. Simmer 5 minutes, stirring occasionally with a wooden spoon.
Pack into hot jars. Be sure syrup covers vegetables. Adjust lids. Process in boiling wat