IME Calculators - Overview

IME was the abbreviation for Industria Macchine Elettroniche S.p.A. IME was established in the early 1960s as a company of the Edison group of Italy. Edison of Italy was a long-estiblished Italian electrical company, founded in 1882 and heavily involved with electrical power generation and distribution. By the 1960s Edison was a large company involved in many aspects of electric power technology, perhaps similar to Ferranti in the UK. It is unclear what if any relationship there may have been Edison of Italy and Thomas Edison’s enterprises in the USA. It is also interesting to note that Edison of Italy appears to have identified electronic calculation as a worthwhile field of development for the early 1960s, just as Ferranti did in the UK.

IME appears to have been the vehicle for the work of Massimo Rinaldi, a talented engineer and one of the original electronic calculator pioneers. IME produced Rinaldi’s first calculator, the IME 84, in 1964. It was very successful and was developed further in the 1960s into a comprehensive calculating system with programming facilities and peripheral devices. Microprocessor technology allowed Rinaldi to develop this concept still further in the 1970s with the MAEL product range. IME survives to this day as QEI srl and has continued to be an innovator in the field of small computers that form large distributed data processing systems. It is interesting to note that in 1990 Dr Stefano Rinaldi became Laboratory Director.

The IME 84 Calculator

IME 84
The IME 84 belongs in the group of the first solid-state electronic calculators, together with the Friden EC-130, the Sharp CS-10A and the Olivetti 101. Massimo Rinaldi must therefore also be recognised as one of the original electronic calculator inventors and it is a pity that very little is known about what led him to design and produce an electronic calculator, nor about how he obtained the support to bring it to market.

The IME 84 was released in 1964. It was a first-generation fully transistorised machine with core memory. It is unique among the first generation machines for having

  • a very well designed user interface that allowed the display of the calculator’s internal registers and,
  • a peripheral interface plug. This interface shows that right from the beginning, Massimo Rinaldi was thinking beyond the single calculator and was imagining how calculators could be part of larger calculating and/or computing networks.

The IME 84 also has a very high standard of industrial design, with a stylish case and very elegant internal construction.

While there will always be debate about which was the first solid state desktop calculator, the features of the IME 84 argue that Massimo Rinaldi should be regarded as the leading first-generation calculator designer and the IME 84 regarded as the leading first-generation machine.

IME 86 S Calculator

The IME 86 is the successor to the IME 84 and is also a first-generation all transistor machine with core memory. The 86S added a square root function and four memory registers but was otherwise similar to the IME 84. The IME 86 is remarkable among first generation calculators for two reasons:

  • It is by far the best implemented first-generation machine. It is free from the bugs, errors and lockups that are seen in many of its contemporaries. It has accurate and comprehensive overflow detection and its decimal point control features rounding.
  • It can connect to a range of peripheral devices so as to form a programmable calculation system.



IME 26 Calculator

IME 26
The IME 26 was a lower cost version of the IME 84. Lower cost was achieved by

  • a smaller digit capacity
  • reduced function user interface
  • four functions only
  • one memory
  • no external interface