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 ¾ d. (ie, 1 pound, 7 shillings and 9 pence, one halfpenny, and 1 farthing) what it will cost to purchase three? £ 4 3s.5 ¼ 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