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Diff — Jacquard Loom

Comparing rev 4 → rev 5

	The Jacquard loom is a weaving machine invented by [[Joseph-Marie Jacquard]] of Lyon, France, first demonstrated in 1801 and patented in 1804. It wove complex figured patterns automatically by reading instructions from chains of [[Punched card\|punched cards]] — making it the first practical machine controlled by a stored pattern of instructions, and the ancestor of every idea of a "program" that followed.

	## The problem it solved

	An ordinary loom interlaces threads by lifting some warp threads and not others on each pass of the shuttle — the pattern is which threads go up. Plain cloth needs simple repeating lifts, but figured fabric — brocade, damask, anything with an image or intricate design — needs a different selection on every pass.

	Before Jacquard, that selection was a person. A draw boy sat above or beside the loom and pulled cords to raise the correct threads, pass after pass — thousands of selections a day, each made by hand. One mistake spoiled yards of silk; one skilled pattern required weeks of labor for feet of cloth. The pattern existed only in the weaver's head and the draw boy's hands — it could not be stored, copied, or moved.

	## How it worked

	Jacquard's attachment — mounted above an ordinary loom — replaced the draw boy with punched cards:

	- Each card carried one row of the pattern, encoded as a grid of holes.
	- A bank of spring-loaded needles pressed against the card each pass. Where a hole was punched, the needle passed through; where there was no hole, the needle pushed its hook out of engagement — and that warp thread stayed down (or rose, depending on the loom's rigging).
	- Cards were chained together into a continuous loop, advanced one card per shuttle pass.

	So: hole = this thread lifts; no hole = it doesn't. One binary decision per thread per row, thousands of decisions per card, chained into sequences long enough to weave pictures. The famous woven portrait of Jacquard — produced by the Lyon firm Didier, Petit et Cie — required about 24,000 cards, and its fidelity still startles people who see it.

	## Why it is the ancestor of programming

	The loom did three things no earlier machine had:

	- The pattern was data. The same loom wove any design; you changed the deck of cards, not the machine. Hardware and its "code" were finally separate things.
	- Programs were portable. A card deck was a library — one atelier's pattern could be punched, sold, shipped, and woven on any Jacquard loom. Patterns became a tradeable commodity in themselves.
	- Errors were in the cards, not the machine. Punch a hole wrong and the cloth came out wrong in exactly that spot — the world's first bugs, traceable to a specific instruction.

	Weavers even developed card-punching as a skilled trade: a designer's draft was transferred to squared pattern paper, then punched row by row — the direct ancestor of "coding from a spec." Lyon developed a whole cottage industry of punchers and card-lacing specialists.

	## Controversy

	The loom was not welcomed. Lyon was the center of French silk weaving, and the draw boys and journeymen whose work the cards automated attacked the early machines — looms were smashed and Jacquard was reportedly dragged from his loom and thrown into the Rhône. The technology won anyway: by 1812 there were some 11,000 Jacquard looms in France, and the riots became one of history's first recorded episodes of labor unrest against automation — decades before the Luddites made the pattern famous in England.

	The economics were unstoppable: figured silk that took weeks now took days, at a fraction of the cost, and the same design could be reproduced identically a hundred times. Lyon's output boomed; the draw-boy trade disappeared. The argument — does a machine that makes goods cheaper destroy the people who made them — is the same one industries have repeated ever since.

	## Lineage to computing

	The loom's cards passed the idea of instructions on paper directly into computing:

	- [[Charles Babbage]] explicitly adopted Jacquard-style punched cards for his [[Analytical Engine]] (1830s) — its operation and variable cards were program and data, and [[Ada Lovelace]]'s 1843 notes assumed that model.
-	- [[Herman Hollerith]]'s 1890 census tabulator used punched cards for data processing, and the company that grew from it — IBM — fixed the card as an industry standard for nearly a century.
+	- [[Herman Hollerith]]'s 1890 census tabulator used punched cards for data processing, and the company that grew from it — [[IBM]] — fixed the card as an industry standard for nearly a century.
	- Program and data punched cards remained the normal way to store a program until interactive terminals arrived in the 1970s — a direct line of descent a century and a half long.

	When computing historians say the Jacquard loom "invented programming," they mean it separated the machine from the sequence of operations it performs — the single idea every language since is built on.

	## See also

	- [[Joseph-Marie Jacquard]]
	- [[Punched card]]
	- [[Charles Babbage]]
	- [[Analytical Engine]]
	- [[Herman Hollerith]]
	- [[History of Programming]]

	[[Category:History]]
	[[Category:Hardware]]

	The Jacquard loom is a weaving machine invented by [[Joseph-Marie Jacquard]] of Lyon, France, first demonstrated in 1801 and patented in 1804. It wove complex figured patterns automatically by reading instructions from chains of [[Punched card\|punched cards]] — making it the first practical machine controlled by a stored pattern of instructions, and the ancestor of every idea of a "program" that followed.

	## The problem it solved

	An ordinary loom interlaces threads by lifting some warp threads and not others on each pass of the shuttle — the pattern is which threads go up. Plain cloth needs simple repeating lifts, but figured fabric — brocade, damask, anything with an image or intricate design — needs a different selection on every pass.

	Before Jacquard, that selection was a person. A draw boy sat above or beside the loom and pulled cords to raise the correct threads, pass after pass — thousands of selections a day, each made by hand. One mistake spoiled yards of silk; one skilled pattern required weeks of labor for feet of cloth. The pattern existed only in the weaver's head and the draw boy's hands — it could not be stored, copied, or moved.

	## How it worked

	Jacquard's attachment — mounted above an ordinary loom — replaced the draw boy with punched cards:

	- Each card carried one row of the pattern, encoded as a grid of holes.
	- A bank of spring-loaded needles pressed against the card each pass. Where a hole was punched, the needle passed through; where there was no hole, the needle pushed its hook out of engagement — and that warp thread stayed down (or rose, depending on the loom's rigging).
	- Cards were chained together into a continuous loop, advanced one card per shuttle pass.

	So: hole = this thread lifts; no hole = it doesn't. One binary decision per thread per row, thousands of decisions per card, chained into sequences long enough to weave pictures. The famous woven portrait of Jacquard — produced by the Lyon firm Didier, Petit et Cie — required about 24,000 cards, and its fidelity still startles people who see it.

	## Why it is the ancestor of programming

	The loom did three things no earlier machine had:

	- The pattern was data. The same loom wove any design; you changed the deck of cards, not the machine. Hardware and its "code" were finally separate things.
	- Programs were portable. A card deck was a library — one atelier's pattern could be punched, sold, shipped, and woven on any Jacquard loom. Patterns became a tradeable commodity in themselves.
	- Errors were in the cards, not the machine. Punch a hole wrong and the cloth came out wrong in exactly that spot — the world's first bugs, traceable to a specific instruction.

	Weavers even developed card-punching as a skilled trade: a designer's draft was transferred to squared pattern paper, then punched row by row — the direct ancestor of "coding from a spec." Lyon developed a whole cottage industry of punchers and card-lacing specialists.

	## Controversy

	The loom was not welcomed. Lyon was the center of French silk weaving, and the draw boys and journeymen whose work the cards automated attacked the early machines — looms were smashed and Jacquard was reportedly dragged from his loom and thrown into the Rhône. The technology won anyway: by 1812 there were some 11,000 Jacquard looms in France, and the riots became one of history's first recorded episodes of labor unrest against automation — decades before the Luddites made the pattern famous in England.

	The economics were unstoppable: figured silk that took weeks now took days, at a fraction of the cost, and the same design could be reproduced identically a hundred times. Lyon's output boomed; the draw-boy trade disappeared. The argument — does a machine that makes goods cheaper destroy the people who made them — is the same one industries have repeated ever since.

	## Lineage to computing

	The loom's cards passed the idea of instructions on paper directly into computing:

	- [[Charles Babbage]] explicitly adopted Jacquard-style punched cards for his [[Analytical Engine]] (1830s) — its operation and variable cards were program and data, and [[Ada Lovelace]]'s 1843 notes assumed that model.
-	- [[Herman Hollerith]]'s 1890 census tabulator used punched cards for data processing, and the company that grew from it — IBM — fixed the card as an industry standard for nearly a century.
+	- [[Herman Hollerith]]'s 1890 census tabulator used punched cards for data processing, and the company that grew from it — [[IBM]] — fixed the card as an industry standard for nearly a century.
	- Program and data punched cards remained the normal way to store a program until interactive terminals arrived in the 1970s — a direct line of descent a century and a half long.

	When computing historians say the Jacquard loom "invented programming," they mean it separated the machine from the sequence of operations it performs — the single idea every language since is built on.

	## See also

	- [[Joseph-Marie Jacquard]]
	- [[Punched card]]
	- [[Charles Babbage]]
	- [[Analytical Engine]]
	- [[Herman Hollerith]]
	- [[History of Programming]]

	[[Category:History]]
	[[Category:Hardware]]