What does a 2019 reverse engineering tool, have to do with a processor from 1972 and obsolete hardware from the Cold War?Ghidra is a free reverse engineering tool released by NSA in May 2019. It contains a language called SLEIGH that defines processors and how they are modelled within Ghidra.The TMS9900 is an old Texas Instruments processor originally manufactured in 1972.The CASE DCX850 is a long obsolete piece of technical equipment used to multiplex communications between Cold War bunkers for the Royal Observer Corps (ROC), which would have been the United Kingdom’s last line of communication network in the event of nuclear war.Aimed at a technical audience, this mostly technical talk (but part history lesson) explains how the SLEIGH language can be used to model a processor and reverse engineer a long obsolete piece of technical equipment, such as the CASE DCX850, where the source code has been deleted or lost.