When performing "time warp slice" rendering for a virtual reality display, the application rendering (30) of the images required for the application that requires the virtual reality display is synchronised (35) to the display frame rate and treated as a "normal" priority task (51) in terms of its scheduling on a host processor. The time warp slice rendering (50) to render the time warp "slices" into the display buffer (21) of the display (4) for scanning out (23) as the display panel is being refreshed is effected as a "real time" priority task (58). To do this, the rendering task setup processing that must be performed on the host processor for that rendering task is scheduled using an earliest deadline first scheduling policy and is synchronised (52) to specific, recurring display events (53) that allow the "real time" priority time warp slice rendering task setup processing on the host processor to be triggered at specific points in the scan out period (23) of the display (4).

Provided herein is a control system for a multiple-mode continuously variable transmission having a ball planetary variator. The control system has a transmission control module configured to receive a plurality of electronic input signals, and to determine a mode of operation from a plurality of control ranges based at least in part on the plurality of electronic input signals. The transmission control module includes a CVP control module. The CVP control module is adapted to implement a cylinder deactivation control process. The cylinder deactivation control process is configured to generate and select a commanded CVP speed ratio and a commanded engine torque based on a desired NVH standard and minimum BSFC.