Getting a Mac to run LogoTurtle on the Logo Floor Turtle robot can be challenging. Windows users can run the LogoTurtle assembler program on the Adafruit Metro Mini right out of the box. But it was discovered that the Metro ships with a pre-loaded sketch that wreaks havoc on a Mac computer if it is not first overwritten by a simple Arduino sketch like Blink. Something about how Mac handles USB serial communication. Note that once you replace the sketch it ships with and load the Logo Assembler on one computer, you should be able to skip the Assembler and run LogoTurtle on any other Mac. If you are setting up several LogoTurtles, say, for a classroom or workshop, you might want load Blink then the Logo Assembler on all your Metros from one Mac, then any other Macs people use should be able to go straight to opening LogoTurtle and getting down to coding.