Can you feel the ALU? - Students compare the simulated and the real world in digital electronics

How does simulation differ from reality? Students at the NORDAKADEMIE were able to experience this by building an ALU both in a software simulation and from real electrical components.

But what is an ALU? An arithmetic logic unit is a central part of every computer. As the name suggests, it allows the computer to perform both arithmetic operations on integer numbers (such as addition) and logic operations (such as AND, OR, XOR). Depending on the ALU, it might be able to perform more complex operations. The ALU built by the students is a simple but actually functional version for demonstration purposes.

In the computer architecture course (Rechnerarchitektur) by Prof. Jan Haase, students were able to build a 4-bit-ALU in both simulated and physical form. Both have their own advantages:

• The simulated ALU (built within the tool Logic Circuits) takes away some tedious steps as well as possible failure points (e.g., broken hardware). This allows for pedagogical reduction. Thus, it is easier for students who have never worked with electronics before.
• The physical ALU allows for more impressive experiences (e.g., smell of soldering, tactile feeling of the electronic components) which cannot be replicated in a simulation. Some learning outcomes of Feisel & Rosa, i.e., Psychomotor and Sensory Awareness can only be achieved this way.

Thus, in the spirit of CrossLab, this experiment offered an accessible opportunity for students to validate their learning experience in different layers of reality and supplement their process using the strength of both a virtual and a physical laboratory.