This view shows the register control mechanism on the inner left-hand side plate.

The black vertical lever pivots about its centre to move the register assembly in and out of engagement with the rotor. The vertical lever is latched in either position by the black horizontal detent lever near the base.

The movement of the vertical lever is controlled by the mainshaft, via the 60° sector and the spring-loaded pawl at its top corner. The notch in the upper surface of the pawl pushes forward on a pin near the top of the lever to disengage the register at the start of the forward stroke. A similar notch under the pawl presses forward on the lower pin to re-engage the register at the start of the return stroke.

The three interconnected levers in front of the vertical lever modify the forward and return operations on total and sub-total cycles.