Was there life before computer?

calculating instruments before the digital era

Volvelles and slide charts

The volvelles are formed by two concentric disks, normally made of cardboard. The top one has a perforated mask, which displays the information marked on the lower part depending on the rotation. The slides chart are the same instrument, but on rectangular shape where two cardboard sheets slide one over the other.

Matthew Paris, a Benedictine monk of 1200, was the inventor. At the time the books were very heavy and to consult the circular tables, used to calculate religious holidays, he had to walk around them: Paris realized that it was more comfortable to turn the tables instead walk up and down!

They replace the manual exploration of the tables needed to identify the stars, to help in first aid, to calibrate mixtures of colors or to choose the wine for an elegant meal.

Petrus Apianus in 1500 created true works of art, with hand-painted engravings, but only with the introduction of the printing press the production of smaller and cheaper models became possible.

Volvelle, Petrus Apianus 1540

One of the first volvelle, inserted in a book, Petrus Apianus ca. 1540

Volvelles for agricultural and navvy use, ca. 1945

Volvelles for agricultural and navvy use, ca. 1945

Parking disc     DNA calculator

Parking disc and volvelle for the calculation of the DNA

Volvelle, 2012

Modern volvelle, inserted in a magazine, 2012

Perrygraf, ca. 1940

Perrygraf, 1940

Slide chart for fuel calculation, 1958

Slide chart for fuel calculation, 1958, and a

Takeoff nomogram

Modern slide chart with takeoff nomogram

Software with analog interface

Software with analog interface

Nicola Marras 2008


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