GE’s Series Six controllers date back to the 1980s and were once the workhorse of heavy industry. They provide 32K words of memory, support Ladder programming and came in several models (60, 600, 6000). They require dedicated programming terminals and serial or parallel interfaces. With no embedded Ethernet and a design over 35 years old, these controllers should be considered for replacement rather than new installation. Spare parts are available, but the technology’s limitations and lifecycle status make long‑term use risky.