Talking of mainframes, many core bank registry functions are emulations of prior systems long embedded into architectures now themselves superseded. Support for tech archaisms has long roots.
The latest IBM z/Architecture mainframe (released in 2024) will natively run binaries compiled for the original IBM System/360, released 62 years ago.
The original architecture has been expanded to 64 bits and can (or should) run linux with older code in virtualization.
However, those mainframes are extremely high performance, high reliably, and high cost. Complete overkill for many companies, who can get away with much simpler/cheaper emulations of the System/360 from 3rd parties, or source code ports to more modern architectures.
https://www.thomaselectronics.com/avionics/head-up-display/
I'm sure there's at least one wealthy Smash Bros. enthusiast willing to pay their asking price and hook up one of their HUDs to a Gamecube to play Melee though.
Good luck selling that to the DOD.
Aircraft can get their service life extended a couple of times before they're parked for good (the B-52 is an extreme example). And the supply system eventually runs out. First of replaceable modules, then the boards, and now the chips.
Man that was such a crushing loss, one of so so so many incredible companies being gobbled up, to steal their value add from the world, to be added to the legion of supplicated talent at the titan's feets.
This industry would be so much healthier, we'd have so much less of all this bullshit, this fuckery, if immortal ultra wealthy companies weren't allowed to forever keep eating their fucking young until there's no one left.
I'm slightly surprised that _virtually_ identical chips are allowed. I expected truly identical chips to be required…