On Wed, Sep 2, 2020 at 10:10 AM ZB <zbigniew2...@gmail.com> wrote: > On Wed, Sep 02, 2020 at 03:56:26PM +0200, Mateusz Viste wrote: > > > https://en.wikipedia.org/wiki/DESQview > > Indeed I recall that name - but somehow never used it before. Does it do > exactly what I've described? Like - for example - I could "split" 486 into > four x86 CPUs, then I can use one instance to boot FreeDOS there, the second > one to boot DOS 6.22 (for comparison), the third one for, say, DR-DOS etc.
No, you can't. I ran it, back in the day. Think of it as a multitasking character mode GUI shell running on top of DOS. You were *not* running multiple copies of *DOS*. You were running multiple *applications* under DOS at the same time. DOS was single-tasking. DV serialized access to it by the various DOS applications, so it was the single task DOS was supporting. It used round robin time slicing, doing a bit of work on each process running under it and moving to the next. It really wanted a (by the standards of the day) fast and powerful machine to be used effectively. A chap I knew back when was a BBS Sysop, and had four nodes of Wildcat BBS software (a popular choice back then) running on a single 25mhz AT clone with a 286 CPU. Other sysops found themselves running multiple PCs on a LAN if they wanted more than one node of the BBS at a time. You needed to experiment with DV to get settings correct to best support what you did, with allocation of foreground and background time slices being key. Conceptually, Windows 3.1 was the next step beyond DesqView. It was a multi-tasking bit-mapped GUI shell on top of DOS. The transition Windows faced was from 16 bit to 32 bit applications. Win95 made a start on that, but DOS was still under the hood. Win98 was the next step. DOS was still there because Win98 needed a real-mode *loader*, but once it was initialized and running, it took over all OS functions and DOS was out of the loop. Win2K was a fully virtualized 32 bit system, and had no need for DOS. (It *did* provide DOS emulation for folks who still wanted to run DOS programs wia the NTVDM DLL.) Win7 and later were aimed at 64bit systems. On a 64bit system, support for 16bit programs went away. If you really needed them, you ran some form of VM under Windows and ran the DOS programs in it. (The vDOS Plus package discussed here is essentially a VM for running 16bit DOS apps.) > Zbigniew ______ Dennis _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
