Classic applications used the Device Manager to open, close, and exchange information with device drivers. Device drivers on Mac OS 8 and 9 could use the Device Manager when they needed to supply a user interface.
In Mac OS X, however, code that communicates directly with hardware devices must use the IOKit API. Therefore, Carbon does not support the Device Manager as an interface for installing or interacting with device drivers. Carbon supports only the Device Manager APIs that allow applications to read and write to open files.
Other software products that have relied on the Device Manager interface in the past (such as desk accessories) should be converted into Carbon applications.