Sony MVS-8000 User Manual page 1200

Left Button: Dragging the bar while holding down the left mouse button
Right Button: Dragging the bar while holding down the right mouse button
Notes
When Left Button selected, even pressing one of the knob parameter buttons in
the menu control block does not display a numeric keypad window.
1200
Screen Saver and Other Settings (Maintenance Menu)
adjusts the parameter assigned to the knob.
adjusts the parameter assigned to the knob.