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AssigneeInternational Business Machines Corporation
InventorsJoan L. Mitchell, Peter Quarendon
Estimating the term…
A compression technique for a character graphics system in which character cell definition bit strings are transmitted from a central processing unit to a display unit. Each cell is divided into a number of slices and each slice into digits. A test is made on whether to compress on a comparison with an all zero slice, the previous slice or the previous slice but one, depending upon the number of digit mismatches that occur when the comparison occurs. Slices are then compressed by comparing each digit with the corresponding digit in the comparison slice and generating a single 0 bit if the digit matches and including a 1 bit and the whole digit if a mismatch occurs. The compression in the central processing unit and the decompression in the display unit is implemented in microcoded routines.
A method for compressing a binary bit string of a predetermined length comprising the steps of:
A digital data display system in which character cell definition bit strings are generated in a central processing unit and transmitted to a display unit including a central processing unit which includes means for compressing bit strings representing digital scan data comprising the information to be displayed said last named means comprising:
Dependencies are inferred from the claim text.