Figure 1-7. The abacus, the most widely used computing device.
THE AZTEC CALENDAR AND OTHER UNNAMED DATA PROCESSING
The Aztec calendar, used around 1000 AD, in Mexico and Central America, was
based on the 52-year cycle of the planet Venus. Once deciphered, it was found to be a
calendar of amazing accuracy. The Aztec calendar could, in a manner of speaking, be
considered the world's first hard disk. This brief survey of early data processing is by no
means comprehensive. It is only intended to give you a feel for the fact that data
processing did not suddenly occur in modern times. In the next section, we take a
quantum leap into the 17th century and the machine-assisted phase.
Figure 1-8. The Aztec calendar, a calculating device of amazing accuracy.