Desk Electronic Calculators

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Royal IC-130

Royal IC-130

Litton Royal IC-130

Distinctive features: Uses a calculator chip manufactured by Fairchild Semiconductor with  electronics transitional between Medium-Scale Integration (MSI) and Large-Scale Integration (LSI).  The display employs unusual 10-segment Vacuum Fluorescent Display (VFD) tubes.

Capabilities: 4-functions.

Display: Display is 12 digits VFD (Vacuum Fluorescent Display) tubes.  Note the half-height zero which was sometimes used in Japanese manufactured calculators of the early 1970s to make reading the display easier if the electronics did not implement leading-zero-blanking.

Technology: Main integrated circuits are Fairchild SL35085X date coded to the beginning of 1972, NEC uPD354D, & other SSI (Small-Scale Integration) ICs.

188 x 267 x 74 mm (7.4" x 10.5" x 2.9").

Made in Japan.
The calculator is marked:
Imperial Typewriter Company, Leicester, United Kingdom."

During a period of diversification in the 1960s Litton Industries of the U.S.A. had bought the Royal Typewriter company, the Imperial Typewriter Company of Britain and the Triumph-Adler Office Machine company of Germany.  Mechanical and electronic calculators were sold under the Royal, Imperial, Triumph, and Adler names.

Inside Royal IC-130

With the top removed showing, from back to front, the power supply, the VFD display tubes and, underneath, the logic board.
Of note are the VFD tubes which have 10 segments and can display a stylised '4', as explained on the page about calculator displays.

Royal IC-130 circuit board

The logic circuit board with the ceramic Fairchild SL35085X and the NEC uPD354D surrounded by dozens of components, including SSI (Small-Scale Integration) ICs, resistors, diodes and capacitors.

Fairchild Semiconductor, one of the giants of the semiconductor world at this time, was only briefly involved with calculator integrated circuits.

The large ICs among a scattering of small ones and other components illustrates the growing takeover of the electronic functions by Large Scale Integrated-Circuits (LSI) at this time.

Vintage Calculators

© Text & photographs copyright Nigel Tout   2000-2020  except where noted otherwise.