After getting my Raspberry Pi I used the one built-in on my MacBook Pro, but the SanDisk SDHC-card showed up as read-only in finder on my mac, and Disk Utility refused to format it. The write protection switch on the card was correctly set, so that made me a bit baffled. But it seems that the internal card reader on the MacBook Pro is a bit finicky.
After Apple decided to redesign the MacBook Pro lineup in 2016, this meant the death of the SD card slot. Most MacBook models previous to this iteration have the slot built into the side, but if not you'll need an extra piece. Depending on which version of the Mac you own, you will need to get a USB SD card reader.
So, there are three ways to put MicroSD into your MacBook Pro. If your MacBook Pro has an SDXC port, you only need an SDXC adapter. Meanwhile, if it only has a USB port, the most comfortable way is by using a card reader. The same method also can be applied to MacBook Pro with the single USB-C port. You might have one of the 'micro' cards that needs a standard SD adapter - I have a 4GB of one of those in my phone, but it came with an adapter. My camera SD cards are standard size and they fit right into the card reader and show up on my desktop. Insert the Micro SD card into the adapter and insert the adapter into your computer. Open a new Finder window. Your SD card will be on the left sidebar under the 'devices' section. Double-click on your SD card, and you should see two folders: DCIM and MISC.
Getting your MacBook to Make SD-Cards Writable
The trick to getting the reader to see the card as writable, you need to put the write protection switch on your SDHC or SD-card in the middle because the sensor in the card reader is flaky. After doing that, the card shows up as writable. So now I have my Raspberry Pi up and running with RaspBMC, and I'm a happy dude!
Macbook Pro Sd Card Adapter
