Abstract: Apparatus is disclosed for selectively prohibiting certain recording operations in a recording and reproducing machine that has generally random accessibility to a plurality of separate portions of information, such as still images recorded on separate tracks of disc packs of a generally standard computer disc drive. The apparatus specifies a group of the tracks as bulk tracks and a second group as working tracks, with the greater proportion of the total number of tracks comprising the bulk tracks which may be a relatively permanent library of the information recorded thereon. The apparatus generally prohibits erasing or overrecording of bulk tracks, unless an enabling signal is generated, which can be produced from an operator controlled keyswitch.