If you formatted the chip via your computer, i read it would likely be more 'compliant' but might not work properly in your digital camera. Technology cannot take over us! - LOL- joke) Maybe this glitch has been worked out in Snow leopard and is the reason why on your friends computer it's working fine.

Fix 1: Check the connections and restart your Mac. To help you fix the SD card not showing up, working, or reading on Mac, we have listed some feasible quick solutions. it's Genius! (We have to take matter into our own hands. Solutions to fix SD card not showing up, reading, or recognized on Mac. No matter where I connect my card reader, i get read only.untill your marvelous suggestion of putting the switch half way in between. I'm using a macbook, and 2 G5 and 10.4.11. So I don't think it's your Macbook pro is at fault, but simply the temperament of the chip having been formatted by a camera. Taking picture out is not problem, but adding pics onto the chip, is what causes the 'read & write' to become 'Read only' in the unlocked position. If it is required, I am OK with reinstalling any software or doing any steps over again.As I was reading in other discussion thread, it appears that when the chip has been formatted by a camera, it becomes a little 'unrully' when you attempt to change its content via a computer. I haven't tried because I haven't been able to yet, but from the given information, all I need to know at the moment is how to boot from the SD card. The SD card I have does contain the full suite of the required Windows drivers. Using a program called WintoUSB, the entire VM to my SD card.A working VM of Windows 10 (will be deleted later).After searching around the internet for a while, I still haven't found a way to do it. Although I'm aware that an SD card would slow things down, I still would like to boot Windows off of the 128 GB MicroSD card. I found a solution where I would have an external MicroSD card with an adapter that fits in flush within the SD card slot so that it's portable as if it was never there.

Sure, 128 GB is definitely enough, but having a Windows 10 partition at the same time completely reduces the amount of storage required for normal day to day usage for me. I have a late 2012 MacBook Pro and I've always had this problem with storage.

How to format sd card on macbook pro