Page 188 - DCAP104_EXPOSURE_TO_COMPUTER_DISCPLINES

Unit 9: Software Development

9.1 History of Programming Notes

The Antikythera mechanism from ancient Greece was a calculator utilizing gears of various
sizes and configuration to determine its operation which tracked the metonic cycle still used
in lunar-to-solar calendars, and which is consistent for calculating the dates of the Olympiads.
Al-Jazari built programmable Automata in 1206. One system employed in these devices was the
use of pegs and cams placed into a wooden drum at specific locations which would sequentially
trigger levers that in turn operated percussion instruments. The output of this device was a small
drummer playing various rhythms and drum patterns. The Jacquard Loom, which Joseph Marie
Jacquard developed in 1801, uses a series of pasteboard cards with holes punched in them. The
hole pattern represented the pattern that the loom had to follow in weaving cloth. The loom could
produce entirely different weaves using different sets of cards. Charles Babbage adopted the
use of punched cards around 1830 to control his Analytical Engine. The synthesis of numerical
calculation, predetermined operation and output, along with a way to organize and input
instructions in a manner relatively easy for humans to conceive and produce, led to the modern
development of computer programming. Development of computer programming accelerated
through the Industrial Revolution.

Figure 9.1. Wired Plug Board for an IBM 402 Accounting Machine

In the late 1880s, Herman Hollerith invented the recording of data on a medium that could then
be read by a machine. Prior uses of machine readable media, above, had been for control, not
data. “After some initial trials with paper tape, he settled on punched cards”. To process these
punched cards, first known as “Hollerith cards” he invented the tabulator, and the keypunch
machines. These three inventions were the foundation of the modern information processing
industry. In 1896 he founded the Tabulating Machine Company (which later became the core of
IBM). The addition of a control panel (plugboard) to his 1906 Type I Tabulator allowed it to do
different jobs without having to be physically rebuilt. By the late 1940s, there were a variety of
plug-board programmable machines, called unit record equipment, to perform data-processing
tasks (card reading). Early computer programmers used plug-boards for the variety of complex
calculations requested of the newly invented machines.

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