Hi, On Mon, Aug 7, 2023 at 7:45 AM Liam Proven via Freedos-devel <freedos-devel@lists.sourceforge.net> wrote: > > On Sun, 30 Jul 2023 at 17:55, Rugxulo via Freedos-devel > <freedos-devel@lists.sourceforge.net> wrote: > > > I believe "task swapping" was one of the main benefits of a 286. > > It's not a 286 hardware feature, no. > > It's a feature of DOS-compatible OSes of the 286 era. It's a software > feature not a hardware one. But it was enabled by XMS memory > management, something that a DOS could only do on a 286 or later.
Wikipedia says the 286 "was designed for multi-user systems with multitasking applications". OS/2 1.x targeted it. > > For > > instance, DR-DOS 7.03 supports "task swapping" on 286s but only > > "multitasks" on 386s. > > Yes, because it uses 386 hardware features to do multitasking. > > > (This probably also goes back to IBM's own > > TopView, which predated DesqView.) > > I don't think TopView did much multitasking at > all, but the thing here is that the DesqView style of multitasking is > done in software and everything has to fit into conventional memory: > all apps share the base 640kB of RAM. Wikipedia says "TopView is the first object-oriented, multitasking, and windowing, personal computer operating environment for PC DOS developed by IBM". > The later 386 type of multitasking doesn't: it's using hardware to do > it it and the software is running in protect mode and has up to 4GB of > virtual address space to play with. > > It's a really big important difference. I'm sure you're more familiar with OS/2 1.x than I am. But clearly that multitasked apps on a 286 in protected mode. > > > Anyone who wasn't booting straight into Windows, and who still used > > > DOS apps, I configured the PC to boot straight into DOSShell instead. > > > I made menu entries for all their DOS apps, and one for Windows 3.x > > > too. > > > > Clearly OS/2 and/or Windows were considered the future. (Novell's > > attempt at improving DR-DOS failed against Win95.) > > Clearly according to whom? OS/2 was "a better DOS than DOS". Originally it was even codenamed "DOS 5", right? The so-called "European MS-DOS v4 that multitasks" used NE format in real mode. That's similar to OS/2 (which also used NE, as did Win 3.x). DOS was never their top priority, but it made them money. Compatibility was important (for a time). I doubt they originally intended to sell multiple OSes, but when you try to support 8086, 286, 386 ... what can you do? Ever-increasing memory amounts needed newer OSes and APIs. > > > [6] By 1993-1994 most PCs booted straight into Windows 3.1 but I made > > > launchers for their DOS apps in Program Manager, and in the > > > background, I hand-optimised their RAM with EMM386.EXE so there was > > > lots of free RAM for those big power-user DOS apps. > > > > Win95 was better. (I still have my overformatted "upgrade" Win95 floppies.) > > That seems a bit like saying that the wheel is better than fire. > > It's a different thing that happened at a later time. They are not comparable. As far as DOS compatibility goes, Windows 3.1 and 95 had a lot in common. > > NT was not aimed at DOS software. It was incomplete in DOS support in > > many ways (and had a much higher footprint). Win95 had DOS features (FAT32, LFNs) that NT didn't get until Windows 2000. > > > DOSShell was a great DOS app launcher and file manager, but didn't have > > > apps. > > > > Apparently "Visi On" in 1983 was the first (and yes, it did allow > > third-party apps in "restricted subset of C" for its VM.) > > I don't really see any connection here, TBH...? Wikipedia says "VisiCorp Visi On was a short-lived but influential graphical user interface-based operating environment program for IBM compatible personal computers running MS-DOS". _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
