A disk drive control architecture provides for the storage and retrieval of data with respect to a rotating media and for the transfer of data with respect to a host in response to host commands. The control architecture provides for the execution of a plurality of background processes for controlling the spin speed of the rotating media, controlling the positioning of the sensor and controlling the reading and writing of data with respect to the rotating media. The control architecture further provides for foreground processes for controlling the background processes. The foreground processes include an interface task, for coordinating the background processes in the execution of host commands and a monitor task integral to the interface task such that the monitor task is capable of implementing diagnostic commands capable of accessing all of the resources of the control architecture. The transfer of diagnostic commands and resultant diagnostic information may be directed through a dedicated data communications channel separate from the data channel used for the transfer of commands and data with respect to the host.