4 ms·

Windows 2.0 for i386 was the first to introduce protected mode and preemptive multitasking. These features had to wait for Intel but it was available in 1987.

kev009 2y ago
In a limited sense, yes, Windows (without NT) increasingly /used/ memory protection hardware over its life but never in a holistic approach as we typically understand today to create a TCB. I don't believe Windows 2.0 implemented preemptive tasking, can you show a reference so I can learn?
- deleted 2y ago
  [deleted]
- jazzypants 2y ago
  I'm not that guy, but the Wikipedia article[1] is a decent jumping-off point, but I also found this blog article[2] talking about the different versions-- although it seems to get a couple things wrong according to discussion about it on lobste.rs[3] Finally, this long article from Another Boring Topic [4] includes several great sources. 1 - https://en.m.wikipedia.org/wiki/Windows_2.0#Release_versions https://en.m.wikipedia.org/wiki/Windows_2.0#Release_versions 2 - https://liam-on-linux.livejournal.com/78006.html https://liam-on-linux.livejournal.com/78006.html 3 - https://lobste.rs/s/4xfswa/what_was_difference_between_windows https://lobste.rs/s/4xfswa/what_was_difference_between_windo... 4 - https://anotherboringtopic.substack.com/p/the-rise-of-microsoft-windows-2x https://anotherboringtopic.substack.com/p/the-rise-of-micros...
  - lproven 2y ago
    That's my blog post -- thanks for the link. The Lobsters discussion was very interesting. Some people in there were extremely knowledgeable, but also very confrontational. Coming straight in going "that's all wrong!" is not a productive way to start a discussion IMHO. I didn't get any very firm conclusions from it. There are some very knowledgeable people out there on the WWW claiming, with convincing arguments, that Windows/286 couldn't run in 286 mode and only gave you 640kB ("conventional memory" in DOS terminology)+ 64kB HMA. Others, including from Microsoft, say no, Windows/286 did run in protect mode and could access 16MB of (segmented) RAM. I do not know for sure who is right.
- fredoralive 2y ago
  AIUI Windows/386 2.x is basically a pre-emptive V86-mode DOS multitasker that happens to be running Windows as one of its tasks. So the GUI itself is cooperative, but between its VM and DOS VMs it can pre-empt. (Windows 3.x 386 mode is similar, with Windows 9x stuff in the Windows VM can pre-emptively multitask, mostly).
  - kev009 2y ago
    Thanks that explanation makes sense to me!

kev009 2y ago

In a limited sense, yes, Windows (without NT) increasingly /used/ memory protection hardware over its life but never in a holistic approach as we typically understand today to create a TCB. I don't believe Windows 2.0 implemented preemptive tasking, can you show a reference so I can learn?

deleted 2y ago
[deleted]
jazzypants 2y ago
I'm not that guy, but the Wikipedia article[1] is a decent jumping-off point, but I also found this blog article[2] talking about the different versions-- although it seems to get a couple things wrong according to discussion about it on lobste.rs[3] Finally, this long article from Another Boring Topic [4] includes several great sources. 1 - https://en.m.wikipedia.org/wiki/Windows_2.0#Release_versions https://en.m.wikipedia.org/wiki/Windows_2.0#Release_versions 2 - https://liam-on-linux.livejournal.com/78006.html https://liam-on-linux.livejournal.com/78006.html 3 - https://lobste.rs/s/4xfswa/what_was_difference_between_windows https://lobste.rs/s/4xfswa/what_was_difference_between_windo... 4 - https://anotherboringtopic.substack.com/p/the-rise-of-microsoft-windows-2x https://anotherboringtopic.substack.com/p/the-rise-of-micros...
- lproven 2y ago
  That's my blog post -- thanks for the link. The Lobsters discussion was very interesting. Some people in there were extremely knowledgeable, but also very confrontational. Coming straight in going "that's all wrong!" is not a productive way to start a discussion IMHO. I didn't get any very firm conclusions from it. There are some very knowledgeable people out there on the WWW claiming, with convincing arguments, that Windows/286 couldn't run in 286 mode and only gave you 640kB ("conventional memory" in DOS terminology)+ 64kB HMA. Others, including from Microsoft, say no, Windows/286 did run in protect mode and could access 16MB of (segmented) RAM. I do not know for sure who is right.
fredoralive 2y ago
AIUI Windows/386 2.x is basically a pre-emptive V86-mode DOS multitasker that happens to be running Windows as one of its tasks. So the GUI itself is cooperative, but between its VM and DOS VMs it can pre-empt. (Windows 3.x 386 mode is similar, with Windows 9x stuff in the Windows VM can pre-emptively multitask, mostly).
- kev009 2y ago
  Thanks that explanation makes sense to me!