Mamiya 120/220 Motorized Film Back RB67 Pro S/SD

Hello:

I have acquired a Mamiya 120/220 Motorized Film Back RB67 Pro S/SD. As it did not come with a manual, I need some help. Can anyone direct me to an online manual for this or explain how it operates?

Thank you

Michael

There are several motorized backs for RB67. See if this helps:

http://www.cameramanuals.org/mamiya_pdf/mamiya_rb_67_motor_drive_roll_film.pdf