|
|
|
|
|
|
by ForOldHack
432 days ago
|
|
|
WSL2 is just a Linux VM, and the POSIX subsystem is just a kluge
I never heard of an OS/2 subsystem for NT, for which Cutler would take extreme umbridge in. I have three charts on my wall( now 4): the Unix timeline, the windows timeline, and the Linux distribution tree,and now a very decent MacOS X timeline. The personalities became containers which is just the windows version of common subsystem virtualization. Containers were based on VirtualPC, but with the genius of Mark Russinivich. |
|
|
It was there from NT 3.1 until Windows 2000; it was removed in Windows XP onwards.
It was very limited – it only supported character mode 16-bit OS/2 1.x applications. 32-bit apps, which IBM introduced with OS/2 2.0, were never supported. Microsoft offered an extra cost add-on called "Microsoft OS/2 Presentation Manager For Windows NT" aka "Windows NT Add-On Subsystem for Presentation Manager", which added support for GUI apps (but still only 16-bit OS/2 1.x apps) – which was available for NT version 3.1 thru 4.0, I don't believe it was offered for Windows 2000.
The main reason why it existed – OS/2 1.x was jointly developed by IBM and Microsoft, with both having the right to sell it – so some business customers bought Microsoft OS/2 and then used it as the basis for their business applications – when Microsoft decided to replace Microsoft OS/2 with Windows NT, they needed to provide these customers with backward compatibility and an upgrade path, lest they jump ship to IBM OS/2 instead. But Microsoft never tried to support 32-bit OS/2, since Microsoft never sold it, and given their "divorce" with IBM they didn't have the rights to ship it (possibly they might have retained rights to some early in-development version of OS/2 2.0 from before the breakup, but definitely not the final shipped OS/2 2.0 version) – the OS/2 subsystem wasn't some completely from-scratch emulation layer, it was actually based off the OS/2 code, with the lower levels rewritten to run under Windows NT, but higher level components included OS/2 code largely unchanged.
> for which Cutler would take extreme umbridge in.
Windows NT was originally called NT OS/2, because it was originally going to be Microsoft OS/2 3.0. Part way through development – but at which point Cutler and his team had already got the basics of the OS up and running on Microsoft Jazz workstations (in-house Microsoft workstation design using Intel i860 RISC CPUs) – Microsoft and IBM had a falling out and there was a change of strategy, instead of NT providing a 32-bit OS/2 API, they'd extend the 16-bit Windows 3.x API to 32-bit and use that. So I doubt Cutler would take "extreme umbrage" at something which was the plan at the time he was hired, and remained the plan through the first year or two of NT's development.
> The personalities became containers which is just the windows version of common subsystem virtualization.
Containers and virtualization are (at least somewhat) successors to personalities / environment subsystems in terms of the purpose they serve – but in terms of the actual implementation architecture, they are completely different.