How can I connect this nexstar controller to my laptop?

[bendiddley]

Hoping someone might be able to help. I have acquired an old Celestron slt mount with just as old nexstar hand controller. I think its a v4 controller. I am using an FTDI USB TO RJ9 4P4C cable to connect controller to the laptop running windows 7. I have installed the correct FTDI driver. I've installed various Celestron stuff including CPWI, HCupdate, nexremote and also the Celestron ASCOM driver. I know the cable works as the computer recognises it, but I can't connect to the controller. I've ensured the controller is plugged in and aligned so as to be able to connect. I've tried connecting using stellarium and Cartes du Ciel and I also tried the Celestron HC updater too to see if I can update the controller but I gather that this controller can't be updated??  Don't know what else to try. Wondering if this controller is too old to be connected to. Anyway, maybe some folk have more of aa clue than me.