The S1-AU Mk1 is a beautifully engineered DIY electronic kit designed with classic 7400 series integrated circuits (ICs). It is a unique and rewarding soldering exercise enabling you to rediscover the hidden logic of computing!

The S1-AU works as an operational 4-bit arithmetic unit, similar to what was found in early computers. It can perform 4-bit binary addition, subtraction, accumulation and comparison.

It doesn’t just blindly process binary arithmetic through 7400 series ICs either. Using ultra-bright LEDs the board shows you the state of each operation, step by step, so you can actually see and understand how a computer really works!