The CoCo SDC is a floppy disk emulator for Tandy Color Computers. It allows you to store CoCo disk images on an SD card, and mount and use them on your CoCo using the on-board SDC-DOS.
This is easily the best modern storage solution for Color Computers. The CoCo SDC was created by Darren Atkinson, and is a huge contribution to the Color Computer community. More information can be found here –> CoCo SDC
Attached here are some pictures of the boards being made.