For John W9RPM -- Serial port adapters are not easy to find these days. I found several USB CW keying cables on Amazon. Search for 'PC Morse to Radio'. https://www.amazon.com/U-CW-6-5mm-Cable-Morse-Radio/dp/B00EZIAESQ. https://www.amazon.com/U-CW-3-5mm-Cable-Morse-Radio/dp/B00EZI7J20 Search for 'PC Morse to Radio' on Ebay to find more cables. Bert N8NN