It was about this point where I started thinking more about the cartridge slot. Originally I had no intention of doing anything with it, and had actually considered printing a plug to close up the hole entirely. But as I started pulling the rest of what would eventually become the reComputer together, ignoring this feature increasingly started to feel like taking the easy way out.

My early concept was to use the same PCB edge connector as the original cartridges, and wire it up to both USB and a few of the Pi's GPIO pins. This would have been relatively easy to implement on the deck side, as the original male connector was actually a separate board that I could have attached new wires to.

This would have opened up some fascinating possibilities in terms of what kind of hardware the carts could support, but it meant the cartridges would all need custom PCBs. Plus, I'd probably have to buy up a lot of PreComputer cartridges on eBay to salvage their female edge connectors and cases, which didn't seem very appealing.

So to keep things easy, I had the idea of trying to recreate the physical design of the VTech cartridges with a printed case that could hold a standard USB flash drive or other small gadget.

Then all I needed to do was mount a female USB extension cable in the cartridge slot, and run that back to the Pi itself. Now cartridges didn't need any special hardware at all, there were simply USB devices plugged into a USB port. Not as impressive technically, I'll admit, but a lot easier to implement.

Here in this final image you can see the USB cartridge adapter installed in the deck, and connected to the Pi that has now joined the power supply in the lower half of the case.