Burroughs C3661  
Written by Accutron on 2009-07-05  

The Burroughs C3661 is a large, four-function programmable calculator with LSI logic and a transistor-driven Nixie display. The C3661 is an improved revision of the C3660, which is a slightly repackaged variant of the Sharp Compet 363P. Unlike the C3660 and 363P, which both use the same Rockwell LSI chipset, the slightly newer C3661 uses a Hitachi chipset. Programs are stored on magnetic cards, and internal memory is volatile.

By far, the most striking aspect of this machine is its large display, constructed from 16 Hitachi Nixie tubes and two additional Hitachi cold cathode display tubes with planar elements.

Burroughs C3661 programmable calculator.

C3661, 16-digit display with overflow indicator and program counter.

The C3661 digits display is constructed from 16 Hitachi CD80P Nixie tubes.

The C3661 overflow indicator and program counter make use of the extremely rare Hitachi HI544 and HI549 display tubes.

C3661, display driver board.

C3661, CPU board. All of the TI 74xx-series TTL ICs used in this calculator have a 1972 date code.

C3661, magnetic card reader mechanism.

This article is part of the [Electronic Calculators] exhibit.

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