Re: [Freedos-devel] GEMMIS, Win3, 386MAX and SBEMU - was: Actually doing stuff with MS-DOS 4.01

[Eric A. <e....@jp...>]

Hi Ralf,

> That is NOT correct. GEMMIS was the interface to allow two (any two) 
> memory managers to work together, nicely.

That is interesting to know, although it sounds like a very
specific use case. For classic DOS extenders, VCPI or DPMI
are enough. You can load DPMI providers using VCPI, or your
OS can directly provide DPMI without having to provide VCPI.

Your CAD software apparently needed something more powerful
than a DOS extender, given that it had to contain its very
own memory manager which then had to cooperate with others.

In the case of Windows, I would say multitasking is the
main difference between V86MMGR and EMM386, which forces
Windows to switch to a built-in memory manager while in
386enh mode, instead of just using/being a DOS extender.

> And the issue is not only for Windows, for example, to take over the 
> memory management FROM EMM386 (or CEMM, QEMM, 386Max, ...) but when 
> exiting, giving that memory management task and CPU state) BACK to DOS.

Sure, you want both aspects if you want GEMMIS. My doubt
is about who apart from Windows wanted GEMMIS. Of course
I am impressed that your CAD was one of those "whos" :-)

Do you have other specific examples of software containing
cooperating memory managers, beyond Windows and your CAD?

Regards, Eric