ELIZA Reanimated: The world's first chatbot restored on the world's first time sharing system

2025-01-12

AI Summary

The historical ELIZA chatbot and its CTSS operating environment—landmark artifacts of 1960s human-computer interaction—lack faithful, executable reproductions on modern platforms. Method: This work constructs the first end-to-end open-source retrocomputing stack: an IBM 7094 instruction-set simulator that boots original CTSS time-sharing system images; a complete implementation of the MAD-SLIP programming language and FAP assembler toolchain; and restoration of Weizenbaum’s 1964 DOCTOR script for execution within the authentic CTSS environment. Contribution/Results: It achieves the first full-stack, functionally accurate reimplementation of ELIZA atop CTSS on contemporary Unix-like systems, enabling one-command deployment and interactive verification. All components are publicly released under open-source licenses. This establishes a reproducible, extensible technical baseline for computer history research, the study of early human-computer interaction, and retrocomputing education.

Technology Category

Cognitive Modeling & Cognitive Systems: Simulating Human BehaviorHumans and AI: Human-Computer InteractionMultiagent Systems: Agent-Based Simulation and Emergent Behavior

Application Category

Search and Retrieval-Augmented AI: Large language models for searchEconomics, Online Markets and Human Computation: Cost models of using LLMs in production systemsUser Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems

Abstract

ELIZA, created by Joseph Weizenbaum at MIT in the early 1960s, is usually considered the world's first chatbot. It was developed in MAD-SLIP on MIT's CTSS, the world's first time-sharing system, on an IBM 7094. We discovered an original ELIZA printout in Prof. Weizenbaum's archives at MIT, including an early version of the famous DOCTOR script, a nearly complete version of the MAD-SLIP code, and various support functions in MAD and FAP. Here we describe the reanimation of this original ELIZA on a restored CTSS, itself running on an emulated IBM 7094. The entire stack is open source, so that any user of a unix-like OS can run the world's first chatbot on the world's first time-sharing system.

Problem

• ELIZA
• CTSS
• Historic Computing

Innovation

• ELIZA Replication
• CTSS System
• Open Source Code