This is the instruction I am sending the board via the Mac Terminal.
/Users/myUserName/Ardunio/build/macosx/dist/tools/avr/bin/avrdude -C/Users/ myUserName /Ardunio/build/macosx/dist/tools/avr/etc/avrdude.conf -pm328p -cstk500v1 -P/dev/tty.usbmodem411 -D -Uflash:w:grbl_v0_8b_edge_328p_16mhz_9600_build20121013.hex –F
That's when I get Yikes!