alt Hacker News>> 8086 can't address 2MB of memory
This was just for illustration, not claiming that actual 8086 does this.
>> Raymond Chen talks a bit about how it worked in Windows 3.x here: https://devblogs.microsoft.com/oldnewthing/20171113-00/?p=97...
And this is the problem, it was very painful just to walk through a 200 KB buffer. This required compiler/runtime tricks, different selector increments in real vs protected mode, and special pointer types. Paging later made this kind of thing look like one flat array, a thing segmentation could not: making non-contiguous physical RAM appear contiguous to the program.
> And this is the problem, it was very painful just to walk through a 200 KB buffer. This required compiler/runtime tricks, different selector increments in real vs protected mode, and special pointer types.
Most of that could be (and often was) hidden by the tooling. If you needed to bypass it, you could, but you didn't need to. That's not very different from today... there's a lot of hidden magic that can be bypassed if you need to for whatever reason.
I'd argue that these are useful engineering abstractions that made the best of a less than ideal situation. (The reality of the world being that there are no "ideal" situations... you have to work with what you have at the moment to solve the problem you have. These days, I'd argue that a pointer into a 'flat' memory space is counter productive to the extent it hides issues around cache hierarchy, NUMA, etc. In 1986, we had to worry that a flat memory space looked discontiguous. In 2026, we have to worry the a discontiguous memory space looks flat.