USB-to-Serial Chip and Driver Vendors Future Technology Devices International (FTDI) FT232 https://www.ftdichip.com/Drivers/VCP.htm Prolific Technology Inc. PL-2303 http://www.prolific.com.tw/ Silicon Labs CP2102 https://www.silabs.com/ WinChipHead (WCH, aka Jiangsu Qinheng Co) CH340/CH341 http://www.wch-ic.com/search?q=CH340&t=downloads Repleo - 3rd party source for high-end macOS drivers for your PL-2303, CH341 and CP2102 USB to Serial devices https://www.mac-usb-serial.com/ It is the pairing of the chip in the programming cable with a compatible device driver in the operating system that allows creation of the virtual serial port that is required to attach the radio to the computer. Without this fully working serial connection, no programming software can read from or write to a radio. For macOS, it is a simple matter to plug in the USB programming cable and type "/dev/cu*" (without the quotes) into Terminal and press [ENTER] to see which chip is in the programming cable. With the output from this command you can choose the correct device driver to pair with the chip. FTDI FT232 (suffix will vary) /dev/cu.usbserial-A6020QSO /dev/cu.usbserial-AH03HQ2G /dev/cu.usbserial-DN00RXF8 /dev/cu.usbserial-DN00V4ZI Prolific Technology Inc PL-2303 /dev/cu.usbserial-1410 Silicon Labs CP2102 /dev/cu.usbserial-0001 WCH (Jiangsu Qinheng Co) CH340/CH341 /dev/cu.usbserialfd140 From here, if necessary, you just install the device driver that matches the chip in the programming cable. FTDI - Nothing should be required. MacOS will use the native Apple FTDI device driver. You can install the FTDI devcie driver from the chip vendor, but from what I have read you should disable the Apple FTDI device driver before you do. https://www.ftdichip.com/Drivers/VCP.htm Prolific Technology Inc - This chip vendor cripples their device drivers so that they do not function properly with unauthorized copies of their PL-2303 chips. Since nearly 100% of programming cables that identify themselves as having a Prolific chip inside are counterfeit, getting a device driver from the chip vendor is not an option for most. What I have done on my MacBook Air is to purchase a device driver for the PL-2303 chip from a 3rd party company (Repleo) for about $9. A bonus is that device drivers for the CH341 and CP2102 chips are also included. http://www.prolific.com.tw/US/ShowProduct.aspx?pcid=41 Silicon Labs - get the device driver from the chip vendor's website https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers WCH (Jiangsu Qinheng Co) - macOS Mojave 10.14 (released in October 2018) and later includes a CH34x driver by Apple so none needs to be installed by the user. For older versions of macOS I would usually recommend getting the device driver from the chip vendor's website. Unfortunately the WCH website is currently unreachable. This github project appears to be a mirror of the WCH macOS device drivers. http://www.wch-ic.com/search?q=CH340&t=downloads Do not install if you have the current macOS Mojave 10.14 or later. macOS Mojave 10.14 (released in October 2018) includes a CH34x driver by Apple. Replio - High-end macOS drivers for your PL-2303, CH341 and CP2102 USB to Serial devices https://www.mac-usb-serial.com/