Abstract: Associative retrieval of data via the technique of superimposed code words is accomplished by circuitry which automatically generates the codes, and which searches through stored code words to find the ones that match a given query code. Code generation is performed using pseudo-random techniques that are reproducible, obviating the need for a pre-prepared code dictionary. Identification of the codes that meet a match requirement is accomplished by logically AND'ing selected bits from the stored codes, said selection being determined by the query code.

Abstract: The random cell scintillations which have been observed in animated dithered displays are substantially eliminated by establishing a hysteresis band about the dither threshold value assigned to each display cell. The hysteresis band is delimited by upper and lower dither threshold values. Determination of whether the intensity of each picture element of the image to be displayed is to be compared to the upper or the lower threshold value assigned to the corresponding display cell is made based on the current state of the cell.