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If we're talking alternate history, DOS 2.0 is a completely different beast than the CP/M-based DOS 1.0. It added things like directories, pipes, device files,

If we're talking alternate history, DOS 2.0 is a completely different beast than the CP/M-based DOS 1.0. It added things like directories, pipes, device files, and hard disk support. If you look at the PC-DOS 2 manual, they broke compatibility with the existing API in a few places to make that happen. They even promised more, such as that it'd eventually have support for multi-tasking. Digital Research was in fact able to deliver on the idea of a multi-tasking DOS. https://en.wikipedia.org/wiki/Multiuser_DOS https://en.wikipedia.org/wiki/Multiuser_DOS Compatibility suffered in some places, as the idea of having to share a system wasn't present in most DOS drivers. It filled its niche, but never broke out of it. I feel if MS-DOS did establish a stronger multi-tasking foundation in those early years, there may have been less of a need of NT for home users. Who knows how many more years the average person would have been using DOS?

pjmlp 5y ago
They did try, that was when MS-DOS 4.0 failure took place.
bitwize 5y ago
Microsoft already had a multiuser, multitasking platform -- Xenix. They had an internal initiative called XenDOS that was intended to make Xenix and DOS more compatible with one another, allowing for development of programs source-compatible with both. That's where all the Unixisms in DOS 2.0 and later came from. DOS 2.0 had a few that later versions didn't -- like a configuration option to select / or - as the switch flag character and full compatibility with use of / as a path separator. XenDOS was likely abandoned when it was found that third-party programs had started assuming direct hardware access in the DOS 1.x days, making transition to a new DOS framework difficult. Windows 9x had full PMT and decent memory protection. It was a separate kernel that ran alongside DOS and populated DOS memory data structures to keep the two systems in sync. It could have been a "home user" successor kernel, but the writing was definitely on the wall at Microsoft that NT with its more robust architecture was the future, as far back as the mid-90s, with 9x acting as a transitional phase.

pjmlp 5y ago

They did try, that was when MS-DOS 4.0 failure took place.

bitwize 5y ago

Microsoft already had a multiuser, multitasking platform -- Xenix. They had an internal initiative called XenDOS that was intended to make Xenix and DOS more compatible with one another, allowing for development of programs source-compatible with both. That's where all the Unixisms in DOS 2.0 and later came from. DOS 2.0 had a few that later versions didn't -- like a configuration option to select / or - as the switch flag character and full compatibility with use of / as a path separator. XenDOS was likely abandoned when it was found that third-party programs had started assuming direct hardware access in the DOS 1.x days, making transition to a new DOS framework difficult. Windows 9x had full PMT and decent memory protection. It was a separate kernel that ran alongside DOS and populated DOS memory data structures to keep the two systems in sync. It could have been a "home user" successor kernel, but the writing was definitely on the wall at Microsoft that NT with its more robust architecture was the future, as far back as the mid-90s, with 9x acting as a transitional phase.