Abstract: A variable width baffle assembly maintains constant, uniform impedance to the flow of cooling air across a vacant space on a partially populated electronic mounting frame for printed circuit board assemblies. The inexpensive but reliable baffle assembly includes end boards mounted on opposite sides of the space and a web member extending therebetween. The web member has a plurality of small apertures distributed thereover with a ratio of aperture area to web member surface area selected to approximate the impedance presented by populated portions of the frame. The web member may be mounted in arched, hinged, corrugated or sliding relationship to accommodate changes in the spacing between end boards so that a single model of baffle assembly can accommodate multiple sizes of vacant spaces.

Abstract: A large, 2 wire, 21/2D core memory includes four, 1K (1024) by 1280, core frames with 1280 Y conductors each stringing and inductively coupling a column of 1024 cores in each of the four frames and 4K orthogonal X conductors each stringing and inductively coupling one row of 1280 cores. A word position within the memory is defined by 5 pairs of Y conductors, a corresponding X conductor from each frame, and selection of relative current directions in the Y conductors. Reading of a 20 bit word is accomplished with 5 sense amplifiers in four rapid sucession read sub-operations. Writing is accomplished in two sub-operations by separately controlling partial select digit currents in each of the 5 pairs of Y conductors. A bidirectional X drive and switching arrangement utilizes overlapping X drive currents and shared circuitry to maximize memory speed and reduce electronic components costs.