The old RS-232 USB dongle I have isn’t supported by Win10 and periodically causes BSODs so I tore into the radio to see what I could do to modify it for USB using an FTDI RS-232 to USB adapter used for Arduinos.
Looking near the serial port they give you vias for the signals you need and the holes are big enough to install .100 pins for experimenting. Top one next to the RS-232 port is ground. Left side one connects to pin 12 (RXD1) and the right side one connects to pin 11 (TXD1) of the MAX232 serial port level translator. These are input side pins on the MAX232 which are exactly what what you need to connect the FTDI adapter!
Wires are then attached. Since I’m using an Arduino serial adapter I’m using the interconnect wires that fit over the .100 headers. It makes it easy when experimenting like this.
The FTDI adapter I have has a power jumper and a 6 pin interface on it as follows:
- DTR
- RXD
- TXD
- VCC
- CTS
- GND
Remove the power jumper. Connect pins 1 and 5 together on the FTDI adapter then connect pin 2 to the .100 pin connected to pin 11 of the MAX232 and pin 3 to pin 12 of the MAX232. Basically you are connecting TX to RX and vice versa.
Power up the radio, connect the USB, and enjoy the blinking green lights as you interact with the radio. 
