PUNCH-CARD DEVELOPMENT: JACQUARD'S PUNCH CARD-
CONTROLLED LOOM (1800).
The punch card, a key feature of the
early computers of the 1930s, was first applied
to a mechanical loom, used for weaving
damask patterns on table linens. Through out
the 18th century, French silk weavers had
experimented with schemes for guiding their
looms by perforated tape, punch cards, or
wooden drums. In all these systems, the
presence or absence of holes created patterns
in the fabric by controlling the way the yarns
were raised or lowered. In 1804, Joseph Marie
Jacquard built a fully automated loom that
could handle enormously complicated designs.
The loom was programmed by a mountain of
punch cards, each card controlling single
throws of the shuttle. To produce a new
pattern, the operator simply replaced one set of
cards for another. It could measure flower
easily as other looms could weave plain cloth.
The Jacquard loom revolutionized the weaving
industry and, in its essential features, is still in
use today. What Jacquard did with punch
cards was, in essence, to provide an effective
means of communicating with the loom. The
language was limited to just two "words," "hole"
or "no hole." The same binary or two-based
system is quite universal in today's modern
computer. And though punch cards were
important for weaving, they were destined to
have their greatest impact on the
Figure 1-13. Jacquard's loom
development of computers.
used punch cards to weave