2016-05-03 17:52 GMT+02:00 Erik Baigar <e...@baigar.de>: > > Dear Experts, > > during discussing the Rolms I came accross the following question: > What was the first (Minicomputer) architecture which offered > memory- and IO protection? I'd define the minimum requirements as: > > - Existence of a superuser mode (Rolm calls this Executive mode) > - Existence of a user mode (With at least two users, Rolm offers 4) > - In superuser mode, IO and memory protection for each user can be > set up individually. > - Any access violation is trapped and handeled by superuser code. > - Of course commands for mode switching and setting up the > memory and IO ranges must exist. > > I have got a real machine (Rolm 1602) having this implemented > and dating from 1975. A document on this "Access Protection Module" as > Rolm calls it also is dated 1975. It consists of a microcode module > which realizes an extension of the 16 bit Nova instruction set and an > additinoal CPU module, taking care of the new modes and supervising > the IO- and memory accesses. > > My question is not regarding virtual memory memory, but regarding > protection (IO and memory) to ensure capsulation of indivitual > processes - not necessarily for multi user environments but e.g. > for safety critical applications... > > Probably OS/2 in 1987 was one of the first home computer OSes to > support memory protection (how about IO protection?), BSD on some > Digital PDP-* was earlier (1977?) but still after the 1602. > > Any hints out there on other "Mini" architectures of that era having > someting similar? > > Erik. > > What about the Norsk Data series of machines, NORD-1, NORD-10 etc.
The NORD-10 had memory protection and paging. Circa 1973. According to the wiki page the NORD-1 had an option to provide virtual memory. The wiki page claim the NORD-1 to be the first mini to have virtual memory (1969). I cannot really tell if this is true. https://en.wikipedia.org/wiki/Nord-1 /Mattis
