B4 Tutorial 14: How does a Computer add ... actually?

In this tutorial, we explore how a computer adds numbers. We start by taking a look inside the adder, which we have re-constructed using relays. These are electromechanical switches. We explore how the switches form logical components and how they are interconnected to form an adder. Because relays are slow and make clicking sounds, we can both see and hear our adder computing. Enjoy!

B4 Tutorials 8-10: We are building a 4-bit computer.

In this tutorial, we are building a simple 4-bit computer capable of addition, subtraction, data retrieval and data storage. We learn how to arrange the boards and connect them with power, data and control wires.

We program the B4 by entering data into the Data RAM and control instructions (the program code) into the Program RAM. For both, we use the Manual Programmer.

Step by step, we then walk through the code and observe how it operates inside the machine.

Why Hardware Engineers Have to Think Like Cybercriminals

The future of cybersecurity is in the hands of hardware engineers, reports IEEE Spectrum. According to Scott Borg, director of the U.S. Cyber Consequences Unit, hackers are increasingly focusing on hardware, not on software. Initially, hackers "focused on operations control, monitoring different locations from a central site. Then they moved to process control, including programmable logic controllers and local networks. Then they migrated to embedded devices and the ability to control individual pieces of equipment. Now they are migrating to the actual sensors[...]”

The issue with computer science is that through decades of abstraction, few people understand what is happening inside the hardware. Everyone is in love with the latest apps, but the hardware is taken for granted.

A system is only as good as its weakest link. No matter how secure we design the 10th level in our software architecture, the system can be compromised if level 0, the hardware, is insecure.

The Australian Digital Technologies Curriculum has a thread on Digital Systems where students explore hardware components, peripheral devices, how systems connect to transfer data and how this can be done securely. So there is an envelope in which hardware and security can be explored in depth.

The reason we developed the Blueberry4™ educational microprocessor is for students can get an understanding of the inner workings of the machine. And yes, we have designed it so that students can hack into it and learn about attack vectors. When you know how to hack you know what countermeasures can be taken. Knowing about the hardware in detail fundamentally helps students to write software that is less prone to cyber attacks.