Fergus Fidget Logic Trainer

Fergus Fidget was a fictional Georgian student imagined by Rev. A. Pegler and used in his short Chapel sermons to personify mischievous behaviours of the boys, By the end of the sermon Fergus had always seen the error of his ways and found redemption. The fidget cube craze of a few years influenced the design the design and within a few days we had the concept for a small tactile device Georgians could manipulate recreationally to explore digital logic gates.

The Fergus Fidget Logic Trainer was first used in the Fall of 2017 with Grade 5 RSGC students at the end of their short introduction to binary numbers and logic gates.


  1. Turning the rotary switch displays a decimal digit on the seven-segment display, thereby setting the target.
  2. The goal is to recreate the binary coded decimal (BCD) equivalent of the digit on the red/green bicolor LEDs. Since there are represented as outputs from four logic gates. The challenge is to set the correct inputs with the paddle switches to achieve the correct output.
  3. There are eight gates in total as each of the four gates (BUF, AND, OR, XOR) can be randomly complemented at the start of each 'game' (NOT, NAND, NOR, XNOR).
  4. A successful match between the displayed digit and its BCD representation results in the speaker playing an audio response.