Washington: Researchers have discovered clues to a lost code in clay balls from Mesopotamia, which was used to keep records, about 200 years before writing was invented.
Christopher Woods, a professor at the University of Chicago`s Oriental Institute, said that the clay balls could represent the world`s "very first data storage system," a website reported.
The balls, which are often called "envelopes", were sealed and contain tokens in a variety of geometric shapes - the balls varying from golf ball-size to baseball-size.
High-resolution CT scans and 3D modelling were used by the researchers to look inside more than 20 examples excavated at the site of Choga Mish, in western Iran, in the late 1960s.
The balls were created about 5,500 years ago when early cities were flourishing in Mesopotamia.
The scans showed that some of the balls featured tiny channels, 1-2 millimeters across, crisscrossing them.
The tokens in balls come in 14 different shapes, which included spheres, pyramids, ovoids, lenses and cones.
The researchers, however, were puzzled when the scans found one clay ball had tokens made of a low-density material, likely bitumen.
The tokens, in this case, had air bubbles around them, which suggested that they had been wrapped in cloth before they were put in the ball, the cloth may have disintegrated over time.
In addition, it seemed that a liquid, likely liquid bitumen, was poured over the tokens after being inserted into the balls.