If your going to use a usb stick to load your gcode files, make sure your usb stick is either partitioned in the NTSF or FAT32 format. Using any other file type may not show files on the controller.
Warning: Formating your usb stick will delete all files on the usb stick
Step 1: Connect your USB drive to the device and click on Open folder to view files option.
Step 2: Right click on your USB drive and click on Format option.
Step 3: From the window, select FAT32 OR NTFS from the drop down bar under File system .
Step 4: Click on Start and OK to commence the formatting process.
Step 5: Once the formatting is completed click on OK.
Step 1. Connect the SD card to the Mac OS X computer.
Step 2. Search for Disk Utility in Launchpad and open it.
Step 3. Select the Drive and click Erase.
Step 4. Enter the new name (OPTIONAL).
Step 5. Select MS-DOS(FAT) for Format.
Step 6. Select Master Boot Record for Scheme.
Step 7. Click Erase. (Depending on the USB Drive size, the operation might take some time.)