This simple mod just makes it possible to place item frames on the bottom or top of blocks.
That's it.
Well, there are some things to note. Maps placed in frames will be represented by a pointer on the map that points south. If you want to make a map room that has maps wrap from floor to wall or ceiling to wall, a small portion of the map won't render because item frames are raised a bit off the block. Because comparators cannot read up or down, they will not be able to read the rotation of the item placed in the frame.
Strait is Open Source and distributed under the CC-BY-NC-SA 4.0 License.