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I love this kind of 'alternate history' computing - OS concepts that could have been, should have been. It makes me wonder about what aspects of modern systems

I love this kind of 'alternate history' computing - OS concepts that could have been, should have been. It makes me wonder about what aspects of modern systems we take for granted. And also what kinds of OS research are going on today, the kinds of systems we might see in the future. Does anyone have any resources to help stay abreast of that?

shadowofneptune 5y ago
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.

shadowofneptune 5y ago

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.