Minolta: how to modify XL-42, XL-64 to add 24 fps
The three cameras in this series, Minolta XL 42, XL 64, and XL 84 all have identical electronics inside. The only exception it the dual zoom speed on the 84.
I looked at the Minolta XL 84 Sound here on the wiki and of course saw that it did indeed have 24 on the speed dial. It is a 5-10 minute, extremely simple modification to allow both the XL 42 & XL 64 to film at 24fps.
First, mark the setting of the film speed knob. Remove the film door and long screw holding the shell on near the handle. Turn the camera over and remove a single screw near the wide side of the telephoto switch. carefully remove the shell. You will see the white plastic pot for the film speed. Turn the shell over and CAREFULLY remove the center screw holding the film speed knob in place. Lift the metal selector flange off very carefully being mindful of the tiny ball bearing that creates the click detent for each speed. Remove the film speed knob. You will see a small plastic tab that can easily be punched out with a small jewelers screwdriver. Carefully do so. Then put the film speed knob back in. Carefully place the small metal flange back over the knob and screw it back together being mindful again of the small ball bearing. Set the film speed switch back to its setting when disassembled. Carefully place the shell back on making certain that all the switches line back up. And there it is. You now have 24fps just like on the XL 84. I've done this modification to both of my cameras.
Photos provided by James E.: