The Olympia RA-20 is a full-function ten-key calculator with an external travelling carriage. The mechanism is a development of a calculator design that first appeared in the late 1950s (US patents 3116873 and 4, filed by Ernst Trümpelmann et al in 1958). The mechanism is based on a pinbox and reciprocating racks, with rotary-gear registers for multiplier and constant storage. The accumulator and counter registers are mounted in the travelling carriage, with a rotary carry mechanism in the body of the machine. Subtraction is accomplished with a second set of reversing star wheels in the carriage.
Keyboard detail (29kb)

Olympia Model 1182 is a basic 8/9-column adding and listing machine from the early 1950s. The mechanism is quite well-made, with a metal base, a one-piece pressed-metal cover, and chrome trimmings. There are function keys for Non-add, Subtract, Total, Sub-total, and Repeat, and a manual clear-entry lever at the left of the keypad.

A version of this machine was re-sold by Monroe in America to complement their line of non-printing rotary calculators. The Monroe 811 incorporates three additional drive gears to re-position the operating handle nearer to the centre of the machine, but is otherwise identical to the Olympia 1182.

Olympia Model AM is a typical low-cost office add-list machine from the 1960s. The 8/9-column mechanism consists largely of plastic and die-cast components, housed in a light plastic case and powered by a small AC induction motor. The functions are the same as in the model above, but with a powered clearing key.

The Olympia RAS-12 is substantial late-model machine with fully-automatic multiplication. It has 11 places in the setting mechanism and 12 in the accumulator and printer, and is powered by a large capacitor-run motor located at the front of the keyboard. The machine operates at about 210 cycles per minute.

Addition and subtraction operate in adding-machine fashion, with the usual total and sub-total keys. Multiplications are entered algebraically, using the "X" and "=" keys. The "X" key transfers the keyboard entry to a set of auxilliary racks in the base of the machine, which then control the sequence of operations when the "=" key is pressed. There is a separate "-=" key for negative multiplication (ie, to subtract a product from an existing total). The results of any calculation are returned to the multiplier racks and are available for re-use, without needing a separate back-transfer operation.

The machine illustrated is dated September 1970, which was well into the electronic era.

The Olympia CD-402 is a compact four-function desk calculator with percent and memory functions. Addition and subtraction operate in adding machine fashion, while multiplication and division operate algebraically in the (now) usual manner. The memory register has add, subtract, sub-total and total keys, with separate +/= and -/= keys for accumulation of products or quotients. A slider switch selects 0 to 7 fixed decimal places, floating decimals, or adding machine mode.

The machine illustrated was built in 1976, but appears to be of European rather than Japanese manufacture. The styling and keyboard layout are consistent with Olympia's earlier mechanical calculators (above), with the additional memory keys colour-coded and grouped separately at the right-hand side. The circuitry uses an American Rockwell 15350 processor, but with a Japanese Futaba display panel and a Fuji power supply module. The display is driven by 34 discrete transistors from the European (BC) series.
Main board - rear view (28kb)

The Olympia CD-430 is a typical 1980s office calculator with square root, percentage, and mark-up functions. The processor and the display module are both from NEC, while the keyboard carries a date code in Canon format. The calculator can be powered from the AC mains, or from two C-size dry batteries for portable use. The battery load is about 600mW.
Internal view (29kb)