Victor Comptometer Calculator Logic  
Written by Accutron on 2017-02-01  

Devices included in this entry:

Victor Comptometer 59138B logic PCA
Victor Comptometer 63175B logic PCA (pictured in thumbnail)

Like many me-too calculator manufacturers in the 1970s, Victor Comptometer chose to base their electronic adding machines on a rapidly evolving series of Rockwell calculator chipsets. Early machines using large chipsets were quickly supplanted by newer models built on increasingly smaller chipsets. The logic PCAs of the Victor 1800 and Victor 1900 are ideal examples of this phenomenon. The Victor 1800, introduced in 1971, makes use of a 7-chip Rockwell LSI chipset. The functionally equivalent Victor 1900, introduced two years later, has a similarly sized logic PCA as the Victor 1800, but the size of the chipset has been reduced to five ICs, allowing the thermal printer drive hardware to fit on the same PCA.

Victor Comptometer 59138B logic PCA, removed from a Victor 1800 adding machine.

Victor Comptometer 63175B logic PCA, removed from a Victor 1900 adding machine.

This article is part of the [Logic & Memory Circuits] exhibit.

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