I&#x27;d say that lag only exists because the UI is running on a full multi-task OS. My microwave display doesn&#x27;t take any noticeable time to wake up when I rotate or press a button, and neither did my radio or my VCR.<p>Smart but task-dedicated devices should probably run the display&#x2F;buttons on a dedicated chip that talks to the CPU asynchronously, to avoid this problem.