Recently I had a need to work with a micro SD card, read and write data for STM32 project. While I used my Macbook Pro to do this it got me thinking about having a backup. How about reusing some of the old parts I had laying around?
Working with various organizations I often wipe and recycle equipment. Usually this is obsolete or non functional equipment. Over the years I have saved some parts as potentially useful. Turns out I had collected three different card multi-readers from various computers. In the end one worked out very well: the TEAC CA-200.
The TEAC unit model CA-200 is something found in various Dell computers or workstations. A unit designed to fit in 3.5 inch floppy drive bays. It has a Dell cable to interface with the system motherboard. Some googling found a relevant discussion on the very useful pinout.ru website. I built a cable using that information just to test things. It worked in Windows 10 much to my surprise (no extra drivers needed).
Knowing this I decided to make a more permanent wiring connection. Opening the unit up its trivial to wire a USB cable directly to the card reader board eliminating the rear connector. Below is a photo of the unit I rewired:

The board is clearly marked for the standard Red, White, Green and Black USB wires.
Final step was to connect this to a Dell laptop and flash the card readers internal firmware to version 4.08. You can find that on Dells website here. This provides support for larger SD cards. I don’t know the exact limit yet but I did read a 32GB micro SD card successfully. I don’t know if you have to run the utility on a Dell computer but it happens I did. Now I’ve got a handy card reader that works not only on Windows 7 or 10 but also on OS X.
Recycle and reuse.