Factorio Forums

+1

Partially implemented in 2.1.
See the latest FFF #442.

Hares wrote: Fri Jun 12, 2026 1:32 pm Partially implemented in 2.1.
See the latest FFF #442.

I don't see anything in that FFF about circuit connections?

macdjord wrote: Mon Jun 15, 2026 7:19 am I don't see anything in that FFF about circuit connections?

This change means you're able to not contaminate one of the wires with the output, so you're able to separate input from output. It's not a full implementation where you're able to individually choose input and output for every value, but in its simplicity it's really good and will not confuse players.

Unfortunately, it's still not possible to "collect" the signal output of multiple connected machines on one wire and set individual values with the other wire since the output of some machine still act as input for another connected machine and thus still contaminate each other. You're able to just share the input wire now, but not the output wire.

Edit: According to FFF #443 it's also possible to select the input wire, so it's definitely the full behavior we players asked for. So it's possible to deliver one value per machine with separate (green) wires, for example separate recipes, and collect all values from all machines with one red wire connected to all machines, for example machine content, and not contaminate the input wire.

Tertius wrote: Mon Jun 15, 2026 10:07 am This change means you're able to not contaminate one of the wires with the output, so you're able to separate input from output. It's not a full implementation where you're able to individually choose input and output for every value, but in its simplicity it's really good and will not confuse players.

Unfortunately, it's still not possible to "collect" the signal output of multiple connected machines on one wire and set individual values with the other wire since the output of some machine still act as input for another connected machine and thus still contaminate each other. You're able to just share the input wire now, but not the output wire.

Maybe input wire would also be configurable as we see pipe connection only which can't read.

We probably know more next Friday and what exactly will be possible.

From what I understand from the collected information over the years that the implementation of the circuit system isn't straight forward and requires a lot of "work arounds".
So unless they rewrite the entire thing from scratch and probably break millions of safe games in the progress it won't be as easy to "simply" add that to the game.

I hope they expand on the details next Friday.

MrFaul wrote: Mon Jun 15, 2026 11:04 am From what I understand from the collected information over the years that the implementation of the circuit system isn't straight forward and requires a lot of "work arounds".
So unless they rewrite the entire thing from scratch and probably break millions of safe games in the progress it won't be as easy to "simply" add that to the game.

They have rewritten it a lot for 2.0 release when added multithreaded computations.

They have, but more in a sense to cope with multi threading and not the underlying principle.
This often involves making a task chunkable that can run independently which circuit networks are by default.
Each network is a chunk, sort off.

To work reliably you have to collect all inputs first and then calculate the output.
I don't even know where the circuit update loop sits, but I expect it to be pretty much the last thing they do in a tick.
It should be a standard scan inputs - > eval - > update loop.
The crux hereby is how does that interact with the rest of factorio's code?

My current educated guess is that machines have only a single in and output buffer for circuit signals and can't distinguish between networks.
When you make a connection to a machine you tell the network "use this buffer in your eval loop".
It would be a major refactor for everything besides circuit devices that where designed for that from the get go to use multiple buffers.

MrFaul wrote: Tue Jun 16, 2026 4:48 am [...]

Toldya!

Recipe and content should be configured per wire or made recepie negative and content positive

Hares wrote: Fri Jun 19, 2026 12:08 pm Toldya!

It is still questionable if this is a rewrite or a "work around".
I never doubted that there is stuff coming they already confirmed changes a long while ago.

Frankly doing anything curcuit related modding wise is still a PITA and I was hoping that they started with a better more modular approach from scratch.
As far as I understand doing anything circuit related even in Factorios codebase is likewise a PITA...

It would be nice to have a reliable hook for modded circuits calculations but there is none, its all done "manually".

+1 to add the output wire selection available in crafting machines to combinators. Having R/G check boxes on the output and else output conditions in a decider would be absolutely amazing for highly compressed circuits, especially for memory cells or DCs with a short circuit! Constant combinators could maybe have the checkboxes on each signal group.

I can't think it would be highly impactful for selectors or arithmetics, unless they receive the 2.0 Decider treatment