A portable roller press that includes a base frame having a pair of opposing stanchions, a drive roller assembly having upper and lower rollers extending between and rotatably mounted to the stanchions, a pair of opposing wings that are hingedly coupled to the base frame and selectively movable between open and closed positions, and an idler roller rotatably mounted to each of the wings. The engine may include a combustion chamber and a working member positioned adjacent the combustion chamber. The position of the nib is determined by inferring a perspective transform from perspective-distorted corners of a tag of known size when sensing the coded data and using the perspective transform together with a known geometry of pen optics to compute the position of the nib. The information received from the host systems on storage units the host systems access and the information probed from the at least one storage system on the storage units available through the storage system are processed to determine an association of host systems to storage units for the at least one storage system.