HN Reader

All in all, this was a very fun project to do, as Windows/386 was really lacking the kind of in-depth analysis that its successors got. I hope to update the project in the future, as well as maybe pivot to something like OS/2.

4 days agoby cwstarblazer

At this point, it starts WIN86.COM (loaded by WIN386.EXE) to start a real-mode copy of Windows in the first VM, otherwise known as the “System VM”.

The DOS-based Windows lineage is definitely very interesting to study and a large contrast to more "normal" operating systems like Linux or NT, because they're actually hypervisors running a VM; and their whole userspace is essentially based around an extended DOS (protected mode) application.

From there, it checks if the resident protected-mode software is a memory manager that it recognizes

What's noteworthy is that EMM386 is also a hypervisor, albeit a very thin one. One could imagine an alternate reality in which x86 gained full virtualisation extensions earlier, causing the hypervisor model to be taken even further and creating a bigger architecture gap between Windows and other OSes.

1 day agoby userbinator

I programmed a lot of real mode x86 assembly under DOS in the late 80s. I didn't have a ton of money, was a kid, and wasn't located close to any tech business (rural western Ohio). The bits and pieces I saw about Windows development on BBSs and in magazines were arcane and strange. I wondered how it all worked but, frustratingly, couldn't get my hands on the documentation or development tools.

Reading articles like this are fun glimpses into a world I dreamt about in my youth. It's a ton of fun, even if I'm probably never going to write any code related to it.

There was a lot of cleverness in the DOS-based Windows family, especially in dealing with constrained resources. I'm not sad it died out (because it lacked the overarching "real operating system" design), but I'm pleased to see it getting brought out into the open.

1 day agoby EvanAnderson

I read it about halfway through before the kiddos started screaming. Overall very good.

One nitpick: maybe provide just a bit more detail regarding how your/your friend came to some of the conclusions. It isn't because I don't believe anything, however I'm just an old timer (somewhat, elder millennial) who likes to know how things work/how you guys game to the conclusions you did. Not a full rundown, obviously, however I did see quite a few assumptions that were only partially explained. Seems to be a good read, however, and I'll finish it tomorrow.

1 day agoby eek2121