Comment by sillywalk
1 day ago
> The core idea, tag memory with unforgeable access tokens at the hardware level instead of leaning on software-defined access control lists, is finally getting real implementation, forty-plus years later.
The IBM System/38 did this around the same time, along with its successor - the AS/400. When the AS/400 switched to POWER (or PowerPC AS), they started using standard RAM, but are still able to have a tag bit for each 16byte(?) pointer using ECC, but the instructions to do that aren't privileged. The AS/400 or "i" as it's now called is still around.
This book has many of them:
https://homes.cs.washington.edu/~levy/capabook/