Joseph Marie Jacquard
Joseph Marie Jacquard was a French weaver and merchant known for his important role in creating programmable machines.
In 1801 the Jacquard loom was first demonstrated. The simplest part of a complex mechanism stood the test of time: it is credited by IBM as having inspired its use case of punch cards in IBM's early computers.
The system replaced prior looms, which required two operators:
- A master weaver in front of the loom would guide the weft thread back and forth between layers of warp thread.
- A draw boy atop the loom raised and lowered specific warm threads at specific times, as directed by the weaver, to form a pattern.
Mistakes were expensive, as a raise or lower of a thread at the wrong time could irreversibly corrupt the pattern. It was also difficult to replicate patterns, relying on an individual weaver's memory.
In the Jacquard machine, holes punched into cards defined the up/down position of the threads at any individual stage in the weaving process. The cards were bound together into a belt which could be drawn up through the machine in sequence. The cards were read by a number of pins, each representing an individual thread, which pushed against the card. When a pin pressed through a punched hole in the card, the corresponding thread would raise. The machine is operated via a foot pedal: stepping on the pedal raises the threads, releasing the pedal ratchets the cards up and over the mechanism.
The cards would be created by card makers, who transferred a weaver's designs from grid paper. Each grid cell represents a line on the final tapestry, or a hole in the punch card.