From 1912:
To 1 quart of strawberries use 1 pint of pineapple cut in portions about the same size of an ordinary strawberry. Weigh the fruit and use the same amount of granulated sugar and let stand ½ hour. Put enough of the fruit and sugar to make 2 jelly glasses full of conserve; boil 15 minutes.
The secret of success with this conserve is in boiling only a little at a time.