speedo cable mk2.5

what year did the mx5 change from cable to electronic sensor? need to source a electronic speedo to match my 2002 gearbox unless theres a way of easly converting the box to cable?

All NA (M1) are cable, all NB (MK2) are electronic. I would guess that NB & NB F/L are interchangeable. What exatally are you trying to achive?