Llaisdy

On Unix-like systems low-level byte-to-byte copying is done with dd:

dd if=[input file] of=[output location]

n.b.: of is a location, not a filename, so you can’t use the file path to your USB stick, as in:

dd if=dfly-i386-gui-2.10.1_REL.img of=/Volumes/MyUSBStick

The path to the device location is required, as in:

dd if=dfly-i386-gui-2.10.1_REL.img of=/dev/disk1

On MacOSX, how to find out the dev name of your USB port is described in this Ubuntu help page. The following will list the currently mounted devices, with their dev names:

$ diskutil list

This will unmount the device, ready for dd:

$ diskutil unmountDisk /dev/[name]

And this will do the deed:

$ dd if=/path/to/input/image of=/dev/[name] bs=2048

Finally, this will make your device safe for removal.

$ diskutil eject /dev/