EC has a demultiplexer hiding in plain sight!
Part 1 here: https://everycircuit.com/circuit/4846082110259200
Here is a 1:2 DEMUX made by harvesting the logic that is embedded into the Binary to 7-segment decoder. The outputs need logic inverters, though, which I've combined with the LED drivers by using PNP transistors.
If you look hard enough at the truth table or a karnaugh map of a Binary to 7-segment Decoder, you may find that if pins 'D' and 'C' are held high, the output truth tables for 'd' and 'f' are the same as a demultiplexer's truth table. That is the whole reason why this works.
For kicks, I updated the LED colors. They add a touch of personality!
Left logic source: Data In
Top logic source: Selection
RGB LEDs: Outputs
1:4 DEMUX https://everycircuit.com/circuit/6625304558436352 and https://everycircuit.com/circuit/6396779649826816
1:8 DEMUX https://everycircuit.com/circuit/5973669939249152
1:16 DEMUX https://everycircuit.com/circuit/4800697325060096
