After I had put together #Block clock I realised how easy it would be to augment the firmware to show the time in ternary (base 3).

As the display board doesn't cater for true ternary indicators like bi-colour LEDs, we have to make do with two side-by-side LEDs of different colours. So either one or two LEDs per trit (ternary digit) depending on the range. Next frustrating project I will get hold of some bi-colour LEDs.

Moreover true ternary for hours and minutes takes a bit of getting used to, so we'll take baby steps and make a Ternary Coded Decimal display this project. 0-9 requires 2+ trits, for 1, 3 and 9, so 5 LEDs (we only need one 9, not both). 0-5 requires 1+ trits for 1 and 3 so 3 LEDs (we only need one 3, not both). 0-2 requires 1 trit, so 2 LEDs. In summary, we need 8 LEDs for 0-59, and 7 LEDs for 0-23. This fits onto #An uninnovative linear LED display which can display two bytes.

The only modification needed to the #8042 clock firmware was to define a binary to TCD map which was generated by a short Python program, and an assembly option to enable this.

This ternary clock (trock) is also mounted on a block of wood. So maybe it's a Block Trock, or maybe Trockenblock, a little dry humour.