All the examples you bring up are from an entirely different time in terms of hardware, a time where one of the major technological limitations were how many pins a chip could have and two-layer PCBs.
Ideas can be good, but fail because they are premature, relative to the technological means we have to implement them. (Electrical vehicles will probably be the future text-book example of this.)
The interesting detail in the R1000's memory model, is that it combines segmentation with pages, removing the need for segments to be contiguous in physical memory, which gets rid of the fragmentation issue, which was a huge issue for the archtectures you mention.
But there obviously always will be a tension between how much info you stick into whatever goes for a "pointer" and how big it becomes (ie: "Fat pointers") but I think we can safely say that CHERI has documented that fat pointers is well worth their cost, and how we are just discussing what's in them.
Ideas can be good, but fail because they are premature, relative to the technological means we have to implement them. (Electrical vehicles will probably be the future text-book example of this.)
The interesting detail in the R1000's memory model, is that it combines segmentation with pages, removing the need for segments to be contiguous in physical memory, which gets rid of the fragmentation issue, which was a huge issue for the archtectures you mention.
But there obviously always will be a tension between how much info you stick into whatever goes for a "pointer" and how big it becomes (ie: "Fat pointers") but I think we can safely say that CHERI has documented that fat pointers is well worth their cost, and how we are just discussing what's in them.