If you don’t need the “disks” to fit into an existing slot, you could print them larger and embed Beyond the cartridges, the PC itself is assembled on a 3D printed frame inside the case.

This floppy-shaped recordable CD is, at first glance, a splendidly retro device. Push it down onto the spindle of the drive and you can look forward to 200 whole Megabytes of storage.