An intelligent disk drive is described which includes means for prioritizing execution of command by maintaining an associated priority with each command in a pending command list and executing the highest priority commands first. The arms are connected to the base end portion. Additionally, the present invention provides for a system for non-contact or stand off chemical detection. The water-repelling agent may be applied as a wax emulsion or in neat wax form. Each nozzle has a first meniscus rim around which an ink meniscus normally forms, and an extended ink flow prevention rim spaced outwardly from the first meniscus rim and substantially encircling the first meniscus rim, arranged to prevent the flow of ink across the surface of the inkjet printhead.