Abstract: An improved servo positioning system for a Winchester disk drive system is disclosed. A plurality of concentric servo tracks are provided on the surface of one disk. Each track is comprised of an equal number of frames of a preterminded length. Four basic frame patterns are utilized. In addition, a frame may also have a code bit in a predetermined position, in order to define the frame as a "one" or "zero" frame. The servo data is read by a dedicated servo head, digitized and fed to a logic array which receives as its only other input an 8 megahertz clock signal. The logic array detects the sync signals present in each frame and generates index, guardband and no sync signals therefrom. In addition, a plurality of windows, each corresponding to a predetermined portion of each frame, is generated. Those window signals are utilized to control a window control circuit which sequentially enables four similar peak dectors, one for each window.

Abstract: An interior storm window construction which is formed with a pair of identical window sashes affording the reversal of the window sashes and a frame comprised of four frame members, three of which are identical in cross section and one of which varies in depth to permit easy insertion and removal of the window sash from the frame. The frame members are formed to be easily adapted to out of square existing window casings. Each of the window panes of the window sashes are coated on one surface with a reflective material, the material on each window pane of the window construction being on a surface which is opposite the coated surface of the other window pane. Each window sash is adapted to slide within the frame formed by said frame members and they interlock along an adjacent edge to afford a seal and support along said locking edge.