How a USB Memory Card Reader Works? Pinout - ETechnoG
PC-3000 Flash. Monolith pinout determination guide. Variant 1 | PC-3000 Support Blog
U0909A (USB2.0 9 Pin Header to SD Card Reader)
spi - Make an SD card installed on PCB readable through USB - Electrical Engineering Stack Exchange
Recover Data from SD card using USB Data cable (memory card) - YouTube
How to build a device to read SPI/SDIO input and convert to USB to read/write data onto a USB storage device from a 9-pin SD card interface? : r/embedded
SD Adaptor, to use SD flash cards with Teensy, Arduino and other AVR boards