Re: IceBreak as an alternative to Apache?

A von Neumann machine is one where the program code is modifiable. The program code for the i is essentially not modifiable, hence non-von Neumann. The primary upside is that program code can be shared among multiple jobs, since it can't be modified.

There's no opinion there, so I don't get your "must think of something else" remark. Are you inferring that I consider the midrange better than other operating systems because they are non-won Nuemann? I do think the midrange is better than any other operating system, but the non von-Neumann nature is only one part of that. And to be pedantic about it, it's not really "non von-Neumann" since the program code can be updated, but only by the operating system not by application programs. So calling it non-von Neumann is more of a convenience term.

And just to expand on that, whether or not read-only code is "common" is not really the point. The point I was making is that the IBM midrange is built around this concept and takes advantage of it in many ways. That's why entire enterprises with hundreds of users could be (and in some cases still can be!) run on machines whose total memory is measured in megabytes, while a typical Windows user needs 4GB just for their desktop machine.

So, yes, other operating systems have shared code. But like so many things, the i has had it for a much longer time. The IBM i - we have technology before technology is cool <smile>.

Joe

Den 31/12/10 22.23, Joe Pluta skrev:

Yes it does. It's called a job. That is the state management on the
i. It's built for that, because all the jobs share the same program
space. The i is a non-von Neumann design in that jobs share an
essentially non-modifiable program space. Thus when you run hundred of

Out of curiosity, why is the above a non-von Neumann design?

Memory mapping shared read-only code is not uncommon these days, so you
must think of something else.