How to Use the Truth Table in Logisim-evolution
A truth table lists every possible input combination next to the output the circuit produces. In Logisim-evolution you can view the truth table of any circuit — and even edit it — from the Combinational Analysis window.
What you need
A saved circuit with input pins and at least one output (LED, output pin, or display). If you don’t have one yet, build the simple AND-gate circuit in our getting-started tutorial first.
Step 1: Open the truth table
With your circuit open, choose Project → Analyze Circuit. In the window that appears, click the Table tab. You now see the truth table of the current circuit: one column per input pin, one column per output, and one row for every input combination.
Step 2: Read the table
Each row is one input combination, counted up in binary. Find the row matching your inputs and read across to see the output the circuit produces. For the AND-gate circuit from the starter tutorial, only the last row (1, 1) shows output 1.
Step 3: Edit the table
Click any output cell to cycle its value. This is handy when you are designing: sketch the behavior you want in the table first, then rebuild the circuit to match. The full workflow is covered in Combinational Analysis: From Truth Table to Circuit.
Step 4: Export and import
The Table tab can export the truth table as a .txt or .csv file — useful for lab reports and documentation. You can also edit the exported file in a text editor and import it back; anything after a # is treated as a comment and ignored.
From table to formula
Click the Expression tab to see the Boolean expression for each output, or the Minimized tab and press Optimize minterms to get the simplified sum-of-products form — the same minimization students do by hand with Karnaugh maps.