I’ve never worked with major enterprise or government systems where there’s aging mainframes — the type that get parodied for running COBOL. So, I’m completely ignorant, although fascinated. Are they power hogs? Are they wildly cheap to run? Are they even run as they were back in the day?
Modern hardware designed to run ancient software. Not all that special.
An older example that’s popular still is the as400. IBM replaced these but a lot of businesses refuse to acknowledge that and maintain these beasts sometimes paying more for parts than MSRP.
Interesting article that’s related.
https://www.gao.gov/blog/outdated-and-old-it-systems-slow-government-and-put-taxpayers-risk
Part of that is the racket that is software licensing for mainframes. Many vendors like CA7 charge based on the machines computational capacity. You can introduce soft limits or send usage reports, but not all vendors accept that to lower your price. Super expensive software costs, at least back when I worked on zOS.
If you ever talk with an insurance guy or system admin, you will understand why as/400 can’t be replaced that easily and most of the time people were unhappy with generic stuff replacing it.
Once while the split of IBM was on table, Microsoft was only interested in AS400 line. They used to do a lot of critical things on them. Yes, even Microsoft.
One can emulate AS400 since the entire thing including hardware and OS is a virtual platform from the start. I am not into financial/insurance/travel so I didn’t investigate if IBM offers a POWER or Xeon replacement. You won’t be able to explain throwing away millions of lines working code to move to some current fashion framework/language. These people make their money from 1/1000s of cents.