AW: When did Memory- and IO Protection Emerge (Esp. in Minis)?

Curious Marc curiousmarc3 at
Wed May 4 19:06:36 CDT 2016

In the not mini but very maxi category, I just learned that IBM implemented memory protection as an RPQ (customer feature) at the request of the MIT folks that built the first IBM time sharing system (CTSS, the predecessor of Multics), on their IBM 7094. Around 1963, unless it was already implemented in the IBM 7090 which would have been 1961. At least that's my cursory understanding of it from . I was very surprised it was that early! 

Sent from my iPad

> On May 4, 2016, at 3:02 PM, Chuck Guzis <cclist at> wrote:
> Is the CDC 1700 considered to be in the family of "minicomputers"?
> (i.e. was the word invented before then?).
> If so, the 1700 had a rather elaborate system of memory and peripheral
> protection.  Circa 1965 (at least that's the date on my manual).
> --Chuck

More information about the cctech mailing list