It is never an issue of “or” (select one) or “and” (select all) but to think in multiples (and not even necessarily ecosystem that is linked). The key is it is

It is never an issue of “or” (select one) or “and” (select all) but to think in multiples (and not even necessarily ecosystem that is linked). The key is it is part of the solution to many different ad possibly unrelated problems. Like playing with pi you have accessed to ports. And playing with mainframe they have access to lots of io ports. And controlled access to thousands of terminals. Pc is (in the older days) isolated calculation machine (excel/lotus 1-2-3/visicalc, words/WordPerfect and multimate/wordstars, real slides vs PowerPoint) and networked machine (unix, internet/decent and SNA). Many different species and some isolated and some linked. Also there are many mainframe in the past if one refers to a machine which has lots of CICS system. Dos/vse is sort of mainframe. Even though it is much smaller than mvs. And music, vms etc. The question is not why strange but rather can they have a place or a niche to survive. And if so, why. And if not really not. For example windows/NT to today windows servers are evolved like bird from the extinct dinosaurs called dec (at least the team is, dna or gene there but not the hardware). If you want one ring (do they still use the most unreliable in operation due to its being most relatable designed token ring?) to rule it all, it is stil mainframe. Strangely in the peak hour, we are considering the transaction processing system as mainframe is not that non-stop and the front end processor sometimes has to be non-mainframe. One thing in perspective is that in 1960-2000 you can use that to handle thousands of terminals with only 16 MB memory. That niche is …