Ok, we’ll come clean. [Design Build Destroy] didn’t really add any memory to his Arduino Nano. But he did get about 1.5K more program space when compared to the stock setup. The trick? … ...

Arduino has also upgraded the onboard flash storage pool. The Uno R4 features 256 kilobytes of solid-state memory, eight times more than the previous-generation chip.

If you want to check out the progress so far, all you need is wire a PlayStation memory card up to an Arduino, write the provided image to it, and stick it in the slot.