As an incremental update, ECS was intended to be backward compatible with software designed for OCS machines, though some pre-ECS games were found to be incompatible. Additionally, features from the improved Kickstart 2 operating system were used in subsequent software, and since these two technologies largely overlap, some users misjudged the significance of ECS. It is possible to upgrade some OCS machines, such as the Amiga 500, to obtain partial or full ECS functionality by replacing OCS chips with ECS versions.