What sections of ISO 13485 cover computer systems?

If you think computer systems that you use for example for: production, for calibration, for service, for warehouse management and similar processes, than managing computer services are under the requirement 4.1.6 which is about the validation of software used in the quality management systems. Such validation must be done prior to initial use, and than after each updated. However, which actions will be taken, how often, which parts of the software will be validated depends on the risks that software have on the quality management system and on the quality of the product. 

There must be a procedure for software validation together with records that proves that validation has been conducted.