On Mon, 20 Feb 2012, Terry Stewart wrote:
So can I gather that there is no clear definition
That is CORRECT.
There has never been a definitive definition, but MANY by marketing people
who do NOT understand.
and Jim's is probably the
nearest thing that comes to defining a mainframe these days...for those
people that use the term?
It's certainly a good EXAMPLE. But, it is NOT a definition.
The whole world is not 370.
The whole world is not Unix.
The whole world is not Windoze.
The best that we've come up with have been differentiation examples.
You can pick up and carry a microcomputer
A minicomputer has casters, or you will need a really solid handtruck.
A mainframe requires a forklift and a union moving crew.
Howzbout: How do you get it up or down stairs?
You can lose a screw in a microcomputer.
You can lose a screwdriver in a minicomputer.
You can lose a scope in a mainframe.
(It is an exaggeration to say that a person could get lost in one. I
think.)
A microcomputer requires a mains outlet.
A minicomputer requires a mains circuit.
A mainframe requires a mains account.
Your neighbors find your microcomputers amusing.
Your neighbors find your minicomputers worrisome.
Your neighbors find your mainframes terrifying.
Your microcomputer won't have a significant effect on your power bill.
Your minicomputer will have a significant effect on your power bill.
Your mainframe will attract the attention of the DEA (hydroponics?) and
HSA.