Apollo Core Rope Memory (Apollo Guidance Computer Part 30)

Marc Verdiell and Mike Stewart explain the design of Apollo Guidance Computer core rope memory and build a custom reader to recover programs.

Core Rope Memory, which contained the programs that landed man on the Moon in the 1960s, is insanely complicated. But that won't stop Mike from making a custom reader for it, so he can recover Apollo Guidance Computer programs lost to history. Mike Stewart's Core Rope Visualizer: apolloguidance.computer/rope/ Apollo Guidance Computer Restoration Playlist: youtube.com/playlist?list=PL-_93BVApb59FWrLZfdlisi_x7-Ut_-w7 Core Memory Videos: youtu.be/AwsInQLmjXc youtu.be/7ozNMgx7WtQ youtu.be/e9ih93tuH1k Look Mum No Computer Core Rope Drum Machine: youtu.be/zytjONYkU94 Mike's Electric Stuff Soviet Dialer: youtu.be/tPT6nIRFI_I Stuff that supports the channel: - Amazon links for the tools I use in the lab (supports the channel if you buy from there) curiousmarc.com/amazon-links - Channel merch on Teespring: teespring.com/stores/curiousmarcs-store - Support us on Patreon: patreon.com/curiousmarc Our lovely sponsors - PCBWay: fast turn PCBs, pcbway.com - Electro-Rent: electrorent.com - Keysight: test instruments: keysight.com - Samtec: connectors: samtec.com - R&D Microwaves: rdmicrowaves.com Get more technical info on the companion site: curiousmarc.com Contact info: youtube.com/curiousmarc/about 00:00 Intro: Apollo Guidance Computer restoration 02:21 What is core rope memory? 05:16 Previous core rope recoveries with our AGC 06:44 Our AGC is sold at auction 07:36 Mike's core rope reader prototype 11:09 Last minute core rope "hack" for Apollo 11 14:04 Software recovered so far 14:48 Trying the reader for the first time and error 17:56 Core rope explanation: data encoding 20:13 Transformer rope is not core rope 21:24 Core rope explanation: reading using bistable cores 26:09 Core rope explanation: molybdenum permalloy cores 28:22 Experimental demo of moly cores 31:49 Core rope explanation: addressing with inhibits 33:59 Apollo core rope simulator, inhibit wires 35:56 Set and reset wires 37:45 Parity wires and the design error 45:02 Mike fixes the reader and tries again 47:38 Success! Congrats Mike!