An easy search of the Wiki brings up this page: https://wiki.batc.org.uk/Portsdown_4_GPIO_Connections
Pin 40. No change from the Portsdown 2020.
Thanks for the reply.
I have done some reading and did notice that . I am not sure what build he is running and with everything that's going on at the moment. It's not making it easy doing it over the air or by phone. There is three of them building Portsdown 4 sharing info sure they will get there.