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Wang LOCI-2 Calculator, Logarithmic Calculating Instrument

The Wang LOCI-2 Programmable Calculator was introduced in early 1965. It used more than 1,000 transistors, no integrated circuits, core memory, and NIXIE Tubes for the display. To dramatically improve the speed of multiplying it actually added logarithms. It supported a printer, Teletype, and punched card reader.


This LOCI-2 belonged to Wang field service and came with a case full of spare boards. The field service people would install known-good boards from the case to repair a customer's calculator. Then they would install the broken board in this LOCI-2 to determine the fault, repair the board, and put the repaired board back in the case. This LOCI-2 came with two punched card reader to load programs. Since this LOCI-2 is a Model 2AC it supports a Teletype as an I/O device using the 1412A board that goes in slot 9.

One of the first programmable electronic calculators, this instrument was announced in 1964 and sold from 1965. It was designed by An Wang (1920-1990) and his associates. Wang, a native of Shanghai, immigrated to the United States after World War II, studied computer science at Harvard University, and worked at the Harvard Computation Laboratory. He started his own business in 1951, producing magnetic core memories and other electronic equipment on order. The LOCI or “logarithmic calculating instrument” was the first product marketed by the company. Two versions of the machine were announced: the LOCI I, which was not programmable, and the LOCI II, which was.

The desktop machine has nine digit keys arranged in an array, as well as a zero bar and a decimal point key. Depressing other keys changes the sign of the number, shifts the decimal point, shifts from the logarithmic to the work register, and shifts from the work to the logarithmic register. Further keys are for arithmetic operations, squares, square roots, inverse squares, inverse square roots, inverse logarithms, and clearance of various registers. To the right are controls for the decrement counter, the program counter, and the operation code. According to company advertising, the machine offers ten-digit precision in addition and subtraction and eight-digit precision in multiplication, division, exponentiation, root extraction, and logarithm computation. It has five storage registers of ten-digit capacity and a ten-digit display, plus a display for the sign of the answer. A cooling fan and a cord are at the back. The card reader attachment that plugs into the back holds program cards.A tag on the front of the machine reads: LOCI-2. A tag on the back reads: ELECTRONIC SYSTEMS AND DEVICES (/) LOCI II (/) MODEL NO. 2AB (/) SERIAL NO. 2734 (/) TEWKSBURY, MASS. U.S.A. A paper tag on the back of the machine indicates that it was serviced 4/28/68, 9/12/68, and 2/9/71.According to a 1964 flier, the machine was to sell for $4,750.00. Kenney says that the initial price was $6,500. Wang Laboratories would go on to sell the 300 series of calculators (from 1966) and the 700 series (from 1969), and to manufacture minicomputers and networked microcomputers.For related objects and documents, see 1980.0096.02 through 1980.0096.10.Compare 1980.0096.01 with the later 1983.0171.01 (a Wang Series 700 calculator), and the even later 2011.0022.01 (a Wang Series 600 calculator).References:There is an extensive discussion of the LOCI II at the website of the Old Calculator Museum. See:
http://www.oldcalculatormuseum.com/wangloci.html



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The Punched Card Reader.

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The top and bottom of the keyboard.



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Wang LOCI-2 Calculator with the cover removed.

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The Wang LOCI-2 Service Case and Service Manual.

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1401A N Register Decoder and Display

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1402A N Register with Binary Adder

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1403B L Register with Binary Adder

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1404A Main Timing

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1405A Miscellaneous Shift Pulse and Control 

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1406A Register with Accumulator, Decimal Counter

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1408A Program and Decrement Counters plus Storages

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1410A 16 Register Storage Containing 10 Digit Decimal + Sign of Each Register (Core)

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1412A Teletype Input and Output Control

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1501A Input Decoder Control




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