https://www.hackster.io/news/peter-bobricius-misenko-s-microsd-card-module-breaks-out-the-signals-and-hosts-an-xtx-xtsd-chip-a90d4e26d402
Peter "Bobricius" Misenko's MicroSD Card Module Breaks Out the Signals and Hosts an XTX XTSD Chip -...
Released as open hardware, these adapter boards can be used for microSD slot tests or XTSD experimentation.