It seems to have been the i960MX and i960MC which had the funky object-oriented memory; they have long since been discontinued, and i can't find any documentation about them online, sadly.
EDIT: There's a passing mention in a book [1]
> The Intel i960 extended architecture processor used a tagged architecture with a bit on each memory word that marked the word as a "capability", not as an ordinary location for data or instructions. A capability controlled access to a variable-sized memory block or segment. The large number of possible tag values supported memory segments that ranged in size from 64 to 4 billion bytes, with a potential 2^256 different protection domains.
Oh, brilliant, thanks. I suspect this evaded my searches because it doesn't say '960mx' in any machine-readable way!
There's some fascinating stuff in here. For example:
> 8.4 Object Lifetime
> To support the implicit deallocation of certain objects while preventing dangling references, the object lifetime concept is supported. The lifetime of an object can be local or global. "Local" objects have a lifetime that is tied to a particular program execution environment [...]. "Global" objects are not associated with a particular execution environment.
> Each job has a distinct set of local objects. No two jobs can have ADs [access descriptors] that reference the same local object. The processor does not allow an AD for a local object to be stored in a global object. Thus, when a job terminates, all the local objects associated with a job can be safely deallocated, and there cannot be any dangling pointers.
The machine was designed, to run Ada programs. Does this line up with how memory management works in Ada? It certainly resembles how it works in Rust!
Ada was designed for environments where dynamic allocation wasn't allowed. So, it doesn't have safe scheme for that. It offers regions, GC, or fast/unsafe deallocation. This is one area where Rust has dramatic improvement. I agree i960 is reminiscent of schemes like Rust. Very forward thinkjng.
Btw, since Im on mobile w/out links, type these into Google: capability computer systems book Levy; Army Secure Operatimg System ASOS. First is great book with many capability architectures like i432. Second is another HW and OS combo designed as secure foundation for embedded, Ada apps. It was interesting.
EDIT: There's a passing mention in a book [1]
> The Intel i960 extended architecture processor used a tagged architecture with a bit on each memory word that marked the word as a "capability", not as an ordinary location for data or instructions. A capability controlled access to a variable-sized memory block or segment. The large number of possible tag values supported memory segments that ranged in size from 64 to 4 billion bytes, with a potential 2^256 different protection domains.
[1] https://books.google.co.uk/books?id=O3VB-zspJo4C&pg=PA189#v=...