Howdy folks, I wanted to get some thoughts and experiences with regards to what sort of EOL handling of mainframe/mini hardware was typical. Part of this is to inform what and where to look for old hardware things.

So the details may differ with era, but what I'm curious about is back in the day, when a mainframe or mini was essentially decommissioned, what was more likely to be done with the central unit, and peripherals if they weren't forward compatible with that user's new system.

Were machines typically offloaded for money to smaller ops, or was it more common to simply dispose of/recycle components? As a more pointed example, if you worked in a shop that had IBM S/3x0, PDPs, larger 3B hardware, when those fell out of use, what was the protocol for getting rid of it? Were most machines "disposed of" in a complete way, or was it very typical to parts it out first, meaning most machines that reached EOL simply don't exist anymore, they weren't moved as a unit, rather, they're any number of independent parts floating around anywhere from individual collections to slowly decaying in a landfill somewhere.

My fear is that the latter was more common, as that's what I've seen in my lab days; old instrumentation wasn't just auctioned off or otherwise gotten rid of complete, we'd typically parts the things out resulting in a chassis and some of the paneling going in one waste stream, unsalvageable parts like burnt out boards going in another, and anything reusable like ribbon cables and controller boards being stashed to replace parts on their siblings in the lab. I dunno if this is apples to oranges though because the main instruments I'm thinking of, the HP/Agilent 5890, 6890, and 7890 series, had different lifespan expectations than computing systems had, and share a lot more of the under the hood components like solenoids and gas tubing systems, so that may not be a good comparison, just the closest one I have from my own personal experience.

Thoughts?

- Matt G.