I had searched around the past few weeks and couldn't find any definitive info on this even though this radio has been around for some time. I recently picked up this radio and decided to make my own cable (well proto-typed with a breadboard). I used this "cable" yesterday and downloaded the "image" file from the radio to my computer using the CHIRP software. I have not uploaded an image to the radio just yet. Basically, the communication connection goes from the computer, through the FTDI USB connector to the TRRS plug (Tip, Ring, Ring, Sleeve) to the radio using only 2 conductors on the TRRS (radio side). The FT-60 TTL is at 3.3VDC, not 5VDC. You can see in the service manual schematic that the "main" (biggest) chip in the radio has TXD2 and RXD2 tied together, which is why TXD and RXD are connected in parallel to the TRRS plug. The connections from the FTDI to the TRRS are simple and only use GROUND, TXD and RXD. Pins 4 (TXD) and 5 (RXD) from the FTDI cable are connected in parallel and connect to the "Ring" conductor just below the "Tip" conductor (assuming a Tip is up, Sleeve is down orientation of the plug). Pin 1 (GND) from the FTDI cable goes to the "Sleeve" conductor. The pins and wire colors below are based on the specific cables I used. As always, it's good practice to verify your own cables/colors/conductors before wiring anything. I've attempted to show a cable "pinout" in the area below with the use of the dash or minus symbol (-). TRRS plug (male)###############FTDI-USB wires Tip-not used Ring-data/clone (white)-------------------4 TXD (orange), 5 RXD (yellow) [these two in parallel] Ring-not used Sleeve-ground (black)----------------------1 GROUND (black) NOTE: There is a specific sequence to follow when "cloning" the radio. These steps were prompted on the screen when using the CHIRP software. I did have some minor trouble getting the radio to clone to the computer at first and it took about 3 or 4 tries. I'm not sure why, but I think it may have been due to the fact that the TRRS wires were loosely fit into the breadboard. Parts/software used for connection: Yaesu FT-60 HT radio Sparkfun FTDI cable 3.3V I/O (part number: DEV-09717) Sparkfun Audio cable, TRRS-18 inch pigtail (part number: CAB-11580) CHIRP software (recent March 2020 version) Windows 10 OS Mini breadboard and hookup wires (to test first) References: CHIRP wiki Sparkfun FTDI 3.3V I/O datasheet Sparkfun Audio cable, TRRS, datasheet FT-60 schematic in service manual FT-60 manual, page 65 * As always, I thought this would be a quick and simple "pinout" post. I tend to write too much rather than too little in the hopes that there will be fewer misunderstandings.