Was there life before computer?

calculating instruments before the digital era

The non-decimal systems

The construction of calculators is complicated by the existence of the duodecimal monetary system, borrowed from Roman Empire and spread throughout Europe by Charlemagne in 779, based on the pound (or lira) with decimal units divided into 20 shillings and 240 pences. France, after the Revolution, was the first country to adopt the decimal system, but the designers have always had to confront with the British currency and other weird systems. In the lower left we have a display in pounds, shillings and pennies, also known as LSD (!): the British are conservative and the symbols are still those of "librae", "solidi" and "denarii" used by the Romans. Alongside there is a display in Rupees.


Display in pounds and rupee

It was not easy: the pound was decimal, but divided into 20 shillings of 12 pences each and the penny was divided into two halfpennies and 4 Farthings. If the price of an item is 1 7s.9 d. (ie, 1 pound, 7 shillings and 9 pence, one halfpenny, and 1 farthing) what it will cost to purchase three? 4 3s.5 d. of course!

Life was difficult for designers, lengths were measured in Imperial (12 inches = 1 foot; 3 feet = 1 yard; 22 yards = 1 chain, etc.), weights and volumes were complicated and calculators used in India had to show results in Lakh, Rupees, (1/100.000 Lak), Anna (1/16 rupee) and Pie (1/12 Anna). India adopted the decimal in 1957 and Britain in 1971, but the British argued that it was too hard to learn!

BriCal Calculator, designed for the Pound Sterling, ca. 1900

In Italy the decimal was introduced in 1806 by Napoleon, who designed the Italian lira immediately adopted in Lombardy and Piedmont. After the unification the Lira became legal in the country by replacing the chaos of the different currencies circulating in the pre-unification states, some with more complex divisions of duodecimal. An example for Tuscany: 1 Lira toscana = 20 soldi = 1.50 Paoli = 0.60 Fiorini (0.84 Lire italiane); 1 Crazia = 5 quattrini = 1 soldo e 8 denari = 0.125 Paoli = 0.083 Lire toscane (7 centesimi italiani); 1 Fiorino = 100 quattrini = 2.5 Paoli = 1.66 Lire toscane (1.40 Lire italiane).

From 1861 were also unified weights and measures: they were dozens and changed at every border, often at each city. The Roman mile was shorter than the mile of Florence or Livorno, similar to the mile of Naples and in any case different from that of Genoa, Venice and Turin. The weights then ...

It 's funny to remember another eccentric monetary system: during the War of Independence, to protest against England, the Americans adopted the Spanish dollar divided into eighths. Hence the expression "piece of eight" to define an object of value but, despite having made the dollar decimal since 1776, the division in eighths remained in use until 1998. Only in that year Wall Street forbade it in the transactions.

Calculators in Eights, Decimal, US Standard and Sterling.

The Americans use the decimal only for the money and still measure in U.S. Standard, where an inch is divided into eighths or sixteenths. There is also a system in hexadecimal (base 16 digits and 10 letters from A to F in which you write 64 100 and 200 as C8): invented in 1859 is now used by programmers as the computer works in multiples of 8 bits.


Displays in sexagesimal and decimal hours

In astronomy the time is sexagesimal while in many production processes is measured in decimal hours, but fortunately addiator and pascaline lend themselves to any kind of carryover. For each unit there is a specific calculator but the coexistence of different systems is confusing: in 1999, the "Mars Climate Orbiter" disintegrated into the orbit of Mars because the instruments measured the distances in U.S. Standard, passing them to the control center who believed to receive in decimal. The chief manager said "People sometimes make errors" and this expensive mistake became known as "metric mix-up".

A modern US Standard calculator

Unit Converter
Input         Result  
Da: Centimetres
A: Centimetres

Nicola Marras 2008


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