He Built the First Chatbot in 1966, Then Tried to Stop It (here's why)

ELIZA, the first chatbot ever made, is running its original 1960s code again on an emulated IBM 7094, and it crashes if you type a number. It's creator spent the rest of his life warning people about AI. The open-source code we ran: - eliza-ctss, Weizenbaum's original ELIZA running on CTSS (Rupert Lane, CC0): https://github.com/rupertl/eliza-ctss - The original 1965 MAD-SLIP source, transcribed (elizagen.org): https://github.com/jeffshrager/elizagen.org/tree/master/1965_Weizenbaum_MAD-SLIP - s709, the IBM 7094 emulator it runs on (Dave Pitts): https://cozx.com/dpitts/ibm7090.html - Inventing ELIZA (MIT Press, 2026): https://mitpress.mit.edu/9780262052481/inventing-eliza/ Sources (the numbers match the on-screen chips): [1] "ELIZA Reanimated: The world's first chatbot restored on the world's first time sharing system". Rupert Lane, Anthony Hay, Arthur Schwarz, David M. Berry, Jeff Shrager. arXiv, 12 Jan 2025. https://arxiv.org/abs/2501.06707 [2] "ELIZA—A Computer Program For the Study of Natural Language Communication Between Man And Machine". Joseph Weizenbaum. Communications of the ACM 9(1), January 1966. https://doi.org/10.1145/365153.365168 [3] eliza-ctss: Weizenbaum's original ELIZA on CTSS, with the s709 IBM 7094 emulator. Rupert Lane, GitHub (CC0). https://github.com/rupertl/eliza-ctss [4] "The Inventor of the Chatbot Tried to Warn Us About A.I.". Jacob Silverman. The New Republic, 8 May 2024. https://newrepublic.com/article/181189/inventor-chatbot-tried-warn-us-ai-joseph-weizenbaum-computer-power-human-reason [5] "The First Chatbot's Multiple Personalities" (adapted from Inventing ELIZA, MIT Press 2026). Sarah Ciston, David M. Berry, Anthony C. Hay, Mark C. Marino, Peter Millican, Arthur I. Schwarz, Jeff Shrager, Peggy Weil. IEEE Spectrum, 15 Jul 2026. https://spectrum.ieee.org/eliza-chatbot-source-code [6] Computer Power and Human Reason: From Judgment to Calculation. Joseph Weizenbaum. W. H. Freeman, 1976. Quoted via Humanist 37.469 (Willard McCarty, 29 Feb 2024) https://www.dhhumanist.org/volume/37/469/ and [4]. [7] "Can A.I. Treat Mental Illness?". Dhruv Khullar. The New Yorker, 6 Mar 2023 (quoting the Journal of Nervous and Mental Disease, 1966). https://www.newyorker.com/magazine/2023/03/06/can-ai-treat-mental-illness [8] "Strengthening ChatGPT's responses in sensitive conversations". OpenAI, 27 Oct 2025. https://openai.com/index/strengthening-chatgpt-responses-in-sensitive-conversations/ [9] "Sam Altman says ChatGPT has hit 800M weekly active users". TechCrunch, 6 Oct 2025. https://techcrunch.com/2025/10/06/sam-altman-says-chatgpt-has-hit-800m-weekly-active-users/ Image credits: ELIZA's code printout, the DOCTOR script and the "Computer Conversations (1965)" folder are from MIT Libraries, Distinctive Collections (Joseph Weizenbaum papers, MC-0383), Copyright 1965 MIT. The two 1965 conversation printouts are © MIT, CC BY-NC 4.0, same collection. Joseph Weizenbaum photo: RIT News & Events, 1982 (public domain). IBM 7094 machine room: NASA Ames Research Center (public domain). The ELIZA conversations on screen are the real output of the restored code, run on our Mac on 23–24 Oct 2026. The machine room is a 3D recreation. Weizenbaum's voice is AI-generated and reads only his published words. ❤️ More about us Radically better observability stack: https://betterstack.com/ Written tutorials: https://betterstack.com/community/ Example projects: https://github.com/BetterStackHQ 📱 Socials Twitter: https://twitter.com/betterstackhq Instagram: https://www.instagram.com/betterstackhq/ TikTok: https://www.tiktok.com/@betterstack LinkedIn: https://www.linkedin.com/company/betterstack 📌 Chapters: