LAB 1

Basic Logic Gates

To determine and verify the behavior of basic logic gates using the Logisim software.

You must bring a laptop to this lab session (Windows or MacOS)
Draw the truthtable for a NOT gate, and also for 3-input AND, OR & NAND gates.
Make another blank column next to your prediction for the actual lab results.
Download the Logisim Software, and verify that it is working.
Download the 7400 Series Integrated Circuit Library Pack - we will use these in later lab sessions.

Logic gates come in several varieties, there are 4 under study in this laboratory session.

The first is the NOT gate, also referred to as an Inverter gate. It outputs the opposite of the value of the input.

The second is the AND gate, it outputs 1 when all inputs are 1, and outputs 0 otherwise.

The third is an OR gate, it outputs 1 when any input is 1, and only outputs 0 if all inputs are 0.

The fourth is a NAND gate, also known as a NOT AND gate, its behavior is the opposite of an AND gate.

The following lab will serve to familiarize you with the function of these logic gates in digital circuits.

Schematic 1

Draw a schematic similar to the one shown left in the Logisim Software.
- Notice that a 3-input AND, OR, and NAND are used.
- Be sure to follow the connections as shown and labelled.
Simulate the full set of possibilities for each gate: ABC = 000 to 111
- You can click the input squares to cycle values.
Include a screenshot or image of your circuit as drawn.
Record the results in a similar chart next to the prelab predictions.

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