[kerravon86]

Exactly. Conventional wisdom said that the 16 MiB barrier was impossible to break. After that was broken, the next thing that was impossible to break was the 2 GiB barrier. That was broken too. I'm talking about 32-bit S/370 code. Obviously IBM independently broke the 2 GiB barrier by switching to 64-bit programming.

But in hindsight, a "properly-written" program from the 1970s would have been restricted to 16 MiB at that time, but magically turned into 2 GiB in the 1980s, and then magically turned into 4 GiB in I think the 2010s (but this is murkier about when you want to start counting - real hardware was only demonstrated in 2022 or 2023 - can't remember).