On an SDHC card, there is a micro-switch on the left hand side, which sets the card as locked or unlocked. Move this to the unlocked position. The card may also need to be formatted in the camera.
Tony your camera is now over 30 years old. THe fact that this is all that is wrong with it is a blessing. But why are you still shooting film? There is nothing you can do on film that can not be achieved on digital.
If there is a film in the camera, then the interlock will prevent the film being wound on. Can you operate the shutter, or is that locked too ? If you are willing to sacrifice the film in the camera, open the back and remove it, then try again with an empty camera.