36bit still in use ?

On Mon, Dec 1, 2014 at 5:03 AM, Lars Brinkhoff <lars at nocrew.org> wrote: I'm not sure why DEC limited the section table on the Model B KL10 to 32 sections, resulting in the 8MW per-process virtual memory limit, but they reserved 12 bits in the section number to allow for future support of 4096 sections, which would result in a 1GW limit. There was room in the EPT/UPT to expand the section table somewhat, perhaps to as many as 128 entries, but obviously not to 4096 entries. There's evidence that DEC intended to go to a two-level section table in Jupiter, with the EPT/UPT having the first level of section table, pointing to pages for the second level section tables. It's my understanding that XKL followed that basic plan, though perhaps the details might not match Jupiter (which doesn't matter since Jupiter didn't ship).