I personally thought the AS/400 was midrange. That's how a co-worker characterized it when he left us to work on OS/400 development (way back in the 1980s).
IBM's own "History of AS/400" web page sort of implies it's midrange:
"For the first time, small businesses, city governments and other medium-size enterprises could set up their own computer networks and connect them to workstations, printers, file servers and even other networks — all running four times faster than what was previously possible."
Maybe System i is more mainframe-y than the original AS/400.
The question got me looking at old AS/400 manuals on bitsavers, and there is some interesting stuff. From the AS/400 handbook:
- Layered machine architecture. This insulates users from
hardware characteristics. It enables them to move to new
hardware technology at any time, without disrupting their
application programs.
- Single-level storage. Main storage and disk storage appear
contiguous. An object is saved or restored on the system via a
device-independent addressing mechanism
- Operating System, OS/400, is a single entity, fully integrating all
the software components (relational database, communications
and networking capabilities, etc.)
I agree with you that AS/400/i has always been called mid-range. I was actually referring to NonStop as usually being called "mainframe" not mid-range, or mini-computer, at least the early pre-RISC models. It's another interesting computer architecture.
For more on the AS/400, there's a book by the lead architect of it, Frank Soltis on archive.org that goes into a lot of detail. It is really quite different from anything else.
IBM's own "History of AS/400" web page sort of implies it's midrange:
"For the first time, small businesses, city governments and other medium-size enterprises could set up their own computer networks and connect them to workstations, printers, file servers and even other networks — all running four times faster than what was previously possible."
Maybe System i is more mainframe-y than the original AS/400.
The question got me looking at old AS/400 manuals on bitsavers, and there is some interesting stuff. From the AS/400 handbook:
- Layered machine architecture. This insulates users from hardware characteristics. It enables them to move to new hardware technology at any time, without disrupting their application programs.
- Single-level storage. Main storage and disk storage appear contiguous. An object is saved or restored on the system via a device-independent addressing mechanism
- Operating System, OS/400, is a single entity, fully integrating all the software components (relational database, communications and networking capabilities, etc.)