That specific system was introduced in the 1980s, but it's even more interesting than that, because it's the last remnant of the Future Systems project which did date to the 1970s:
https://people.cs.clemson.edu/~mark/fs.html
> The IBM Future System (FS) project was a design effort to succeed the IBM S/370 architecture that was adopted company wide in 1971. FS was based on a single-level store with automatic data management. The project is reputed to have cost more than $1B when it was cancelled in February 1975, but the single-level store idea was adopted by System/38, AS/400, and iSeries.
It had interesting effects on IBM:
> Most corrosive of all, the old IBM candor died with F/S. Top management, particularly Opel, reacted defensively as F/S headed toward a debacle. The IBM culture that Watson had built was a harsh one, but it encouraged dissent and open controversy. But because of the heavy investment of face by the top management, F/S took years to kill, although its wrongheadedness was obvious from the very outset. "For the first time, during F/S, outspoken criticism became politically dangerous," recalls a former top executive."
Beware the Superproject!