The population is beginning to take its toll on the fps. I got about 30 throughout the year. On the other hand, the new versions are very stable. I didn't have a single crash.
I fixed the obsidian bug, so obsidian is now a usable stone.
The obsidian generator takes up three floors, and I've left a good deal of infrastructure, so I'm going to leave notes on how to use it. Using these notes, it should be easy to cast a second floor above the first.
First, I decided to use only half of the tower for the generator. The other half contains a stoneworks and the room of my dwarf. This is to minimize the amount of space that the water has to spread over. The following diagram shows where obsidian should be cast. Namely, the blue area should be dug out and cast in.
The second floor is a little bit of digging and a few lever pulls away from being completed, so I will leave my plans for using it. First, make sure that the wall around the second floor is complete (at this point, the dwarfs just need to finish constructing the last one). Then, make sure that the four microcline towers have doors or are otherwise sealed on the second and third floors.
Next, channel away the obsidian floors on the third floor.
This should leave you with open space on the third floor and a flat floor on the second. After this, it is time to pull the lever.
First pull lever 1 (the note title is Obsidian Gen Magma). This will flood the second floor with magma. Because the pump is on the same level, overflowing should be impossible. When the magma has a uniform level of 2 or more, pull the lever again to close the gate.
Then pull lever 2 (Obsidian Gen Water). This may cause some overflow. It may also take a while. When all of the magma has turned to obsidian, shut the water off.
The third floor needs to remain open to allow the water to access the magma below.
I claim no liability for anyone who tries to use the higher water and magma spouts, as there needs to be higher walls for them to be used safely.
The outer walls were built with the intention of removing them at a later point to make the obsidian walls the exterior of the tower, which is why I've left a space of obsidian along the edges.