Below is a basic not Gate using nandgate.
Not Sure why output is X, when I change it to Output properties to three state no, I can't modify circuit.
Some times, these issues go away when I restart logisim.
some more weird issues...
My Alu output shows
I tracked down that to below highlighted Mux gate
When I tried to modify that, it gives this popup
when I click ok and try to change input,
x in output will be gone.
All my subcircuits are fine individuallly, when combining them to make ALU, these kind of weird issues popup, when drilling down, we will see results like above.
Faced same issue with adder, but restarting logisim fixed the issue.
Any ideas or pointers ...?