Abstract: In film copying apparatus (FIG. 3) in which a master film 13 and unexposed copy film 13 are drawn past an exposure gate 12 by a drive sprocket 15, the sprocket teeth 16 have a curved profile which engage with film sprocket holes such that the upper film lags behind the lower and the copy is incorrectly aligned with respect to the sprocket holes. Film strip registration means for correcting misalignment at the exposure gate comprises suction means 20 having a vacuum chamber 21 with apertured pad 23 by which the copy film is diverted out of the plane of the master film thereby increasing its path length between exposure gate and drive sprocket and advancing it at the exposure gate to re-establish registration with the master film.

Abstract: A circuit assembly comprises a planar substrate 10 supporting, on a surface 11, connectors 14 and modules 12, the connector pieces of the connectors, and the module leads, both extending at least substantially parallel to said one major substrate surface, and the modules are clamped to the substrate in a readily releasable manner by means 40, so that a module can be replaced readily, for example, when faulty, and there may be a resilient part 48 of the clamping means between each module and a rigid part 41 of the clamping means, so that the module is not damaged by the clamping action; possibly the resilient part being provided by a composite structure of the resilient part and insulating sleeves 13' for module leads; and the clamping means including at least part of the connectors, so that the required clamping action is at least partially between the substrate and the connectors.