Supervisor

Suitable for

Abstract

The Royal McBee LGP-30 was an early desk-sized computer developed in 1956. It used a clever design, with a large spinning drum holding 16KB of memory, from which bits were read and processed sequentially. Famously, this computer was used by Edward Lorenz, running code written by Ellen Fetter and Margaret Hamilton, to discover and demonstrate the core properties of chaotic systems: deterministic nonperiod flow and sensitive dependence on initial conditions. Lorenz’s original paper presented the first hand-drawn plots of what is now known as the Lorenz attractor (www.astro.puc.cl/~rparra/tools/PAPERS/lorenz1962.pdf). It described in detail how the calculations were performed and provided printouts of computed results over multiple iterations. Unfortunately, the original code that generated these results is lost. In this project, you will use a simulator of the LGP-30 to reverse engineer this lost code from the details in the paper. In doing so, we hope to rediscover the design choices, made by Ellen Fetter and Margaret Hamilton, that were necessary to perform this computation on such a limited computer.