The Weavers: Memory and the Moon

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In 1965, engineers were building a computer to fly men to the moon. It had to survive a rocket launch and the vacuum of space. It could not be erased by a power failure, a hard landing, or anything short of physical destruction. They needed to make the code permanent. They needed to weave it.

In this episode

  • Hilda Carpenter - MIT technician who assembled the first magnetic-core memory plane
  • The Raytheon weavers - Textile workers and watchmakers recruited to encode Apollo's computer
  • The Fairchild Semiconductor plant - Where Navajo women built integrated circuits so men could walk on the moon


Episode Music



Additional Reading

CuriousMarc. (2019). Core memory explained and demonstrated [Video]. YouTube. https://youtu.be/AwsInQLmjXc

Nakamura, L. (2014). Indigenous circuits. Computer History Museum. https://computerhistory.org/blog/indigenous-circuits/

Rankin, J. L. (2022, February 18). Core memory weavers and Navajo women made the Apollo missions possible. Science News. https://www.sciencenews.org/article/core-memory-weavers-navajo-apollo-raytheon-computer-nasa

Shirriff, K. (2019). Software woven into wire. Ken Shirriff's Blog. https://www.righto.com/2019/07/software-woven-into-wire-core-rope-and.html

Stark, L. (2018). Hilda wove all those wires [Zine]. https://www.liza-stark.com/projects/zines/hilda.html

Virginia Museum of Fine Arts. (2017). "Hear my voice" artist profile: D.Y. Begay [Video]. YouTube. https://www.youtube.com/watch?v=v9wmz5rf1NU

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Found in the Machine is a narrative technology podcast about the forgotten history of computing, software, and the internet. Hosted by Daina Bouquin, each episode uncovers the true story behind a piece of computer history. These are the forgotten people, decisions, and accidents that quietly shaped the digital world. 

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{transcript}

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Imagine the year is nineteen sixty-five. You are building a machine to fly human beings to the moon. It has to survive the violence of a rocket launch. It has to survive the freezing, radiation-soaked void of space. And it has to fit inside a small spacecraft in an era when computers need to live inside large rooms. How do you guarantee the code will survive? You don't type it. You weave it. I'm Daina Bouquin. This is Found in the Machine. MIT. 1953. A laboratory bench. Bright overhead light. The smell of solder and warm metal. A black lab technician named Hilda G. Carpenter sits down with a spool of fine wire and a tray of tiny magnetic rings and begins to build something that has never existed before. The rings are smaller than shirt buttons. Smaller really than most things you'd touch in a day. Each one is a ferrite core, a tiny donut shape that can hold a charge or not hold a charge. That can mean one or mean zero. She picks up a wire. She threads it through the center of a ring. That is a one. She routes the wire around the outside of a ring, bypassing it entirely. That is a zero. One, zero, one, zero. She does this again and again for hours, for days, weeks. When she is done, software exists inside hardware. Information is not stored on a spinning disk or punched into a card. It is woven into a physical object. A plane of magnetic-core memory. The first one ever assembled. It becomes the standard form of computer memory for the next 20 years. Every computer that runs on magnetic core memory for two decades runs on a foundation that was physically laid by Hilda Carpenter's hands. There is a photograph of her in a technical journal from 1956. Her hands, the rings, the wire. The men who worked alongside her remember her efficiency, her precision, the particular stillness she brought to work that required absolute stillness. Decades later, many of them could no longer remember her last name. Now back to 1965. Back to the rooms in Massachusetts where the Apollo software is being made. The moon-bound computer's memory is made of ferrite cores. The same tiny donut-shaped rings held the carpenter once threaded by hand. If a wire passes directly through the center of a core, the computer reads it as one. If the wire goes around the outside, the computer reads it as a zero. One cubic foot holds 72 kilobytes of data, 18 times more dense than standard magnetic core memory. And it is permanent by design. The code cannot be erased. Not by a power failure, not by a hard landing in the silent dust of the moon. Not by anything short of physical destruction. The engineers call it core rope memory. The code is literally hardwired in. And someone has to do the weaving. The ferrite cores are microscopic. Workers have to peer through magnifying glasses just to see what they are doing. The contractor Raytheon realizes they do not need engineers. They need people with steady hands and extreme precision, and the patience to thread a needle through a space that is barely there. They hire women. Skilled women from the New England textile industry. Former employees of the Waltham Watch Company. Women who have spent years fitting tiny springs and gears into spaces smaller than a thumbnail. Picture them at long desks in white smocks under bright task lamps. Their backs curved over the work. Hour after hour, season after season, a hollow wire-filled needle passing back and forth through a matrix of tiny eyelets, through the core around the core. One, zero, one, zero. The weaving of a single module takes about eight weeks. It costs fifteen thousand dollars. If the code needs to change even by a single bit, the work has to stop and begin again. The program has to be frozen months in advance, committed to wire and ring in the particular steadiness of human hand. Each core has 192 wires passing through it. A single mistake in the entire module is flawed, useless. NASA inspectors hover. Federal agents hover. There are supervisors they call the rope mothers. The men and women who oversee all of it, who are responsible in the end for what gets woven, for what goes up. Most of them were actually men. The engineers have a name for the whole operation. They call it the LOL method. The work that will take human beings to the moon. A thousand miles away in Shiprock, New Mexico, something similar is happening. Unemployment on the Navajo Reservation is hovering around 40%. For years, tribal leadership has been trying to attract outside investment. In 1964, tribal chairman Raymond Nakai opens the reservation to outside businesses. Tax breaks, subsidized construction. A workforce with almost no other options. Fairchild Semiconductor hears about it. They come to Shiprock. They build a plant. And they train Navajo women in the assembly of integrated circuits. Components also smaller than a fingernail. Made of silicon and metal, requiring electrical connections placed with microscopic precision. The women bend over their stations for hours, peering through microscopes. They place components onto chips with tweezers. They solder connections you could not see with the naked eye if you tried. Their backs hurt. Their necks hurt. They do not stop. At its peak, the plant employs more than a thousand workers. Most of them are Navajo women. To celebrate the dedication of the plant, Fairchild produces a brochure. First page, a large photograph of a Navajo rug. Geometric. Brown and black and white. Beautiful. Next page, a photograph of an integrated circuit. Also geometric. Also intricate. Then photographs of women at looms. Women at microscopes. The brochure says, quote, the blending of innate Navajo skill and semiconductor's precision assembly techniques has made the shiprock plant one of Fairchild's best facilities. "Innate". As in born with. Natural. Not learned, not earned, not transmitted across generations through years of patient instruction. Just present. Like eye color. Here is what innate erases. Navajo weaving is one of the most sophisticated textile traditions in human history. A master weaver has spent years learning from her mother and her grandmother. The patterns encode specific knowledge, cosmology, clan histories, ceremonial meaning, geometric systems developed and refined across centuries. A Navajo rug is not decoration. It is a record. It is argument and memory and identity woven into wool. Contemporary Navajo weaver D. Y. Begay gave an interview in 2017. She said, "I paint with my yarn to tell my story about where I come from." She shared that she teaches her nieces not to swear in front of their looms. This is knowledge that is taught, passed from person to person across generations. Building bleeding edge microchips is also something you have to learn. In 1975, NASA published a report summarizing the Apollo missions. It spoke at length about the flawless performance of the computer software, the adaptability, the precision, the extraordinary reliability of a system that had to work perfectly the first time, with human lives depending on it. The report did not mention the women at Raytheon. It did not mention the women at Fairchild Semiconductor. Not one name, not one line. Researchers trying to piece this history together now face a simple fact. Nearly every woman who could tell these stories firsthand is likely gone. The accounts of the engineers were carefully preserved. No one collected the oral histories of the weavers. We don't know where these women were as men landed on the moon. Whether they sat in front of a television and recognized, in the thing happening on the screen, the work of their own hands. No one thought the question was worth asking. But their code is still up there sitting in the dust. I'm Daina Bouquin. This is Found in the Machine.

{tags}

Apollo Guidance Computercore rope memoryNASA historywomen in computingNavajo historyFairchild SemiconductorHilda CarpenterRaytheonspace race historyhidden figureshistory of computingmagnetic core memorywomen in techApollo program