The Open Group claims the copyright on the POSIX specifications. If APIs can be copyrighted and this copyright includes all implementations, then it would be problematic for all open source *NIX systems. Of course, they might decide to provide a license that's valid for everyone except Oracle (though writing such a license in a way that's GPL compatible would be very hard, so glibc might be in trouble).

The thing that killed DC in the war of the currents was that step up and step down transformers for AC are easy and cheap to build, but doing the same thing for DC caused a lot more loss (one of the simplest ways of doing it was to convert to AC, do the voltage change, and then convert back to DC). For long hauls on the grid, you want a much higher voltage than in houses. Now, however, it's relatively cheap (both in terms of convertors and in terms of loss) to produce DC-DC converters. USB-C supports 5V (up to 2A), 12V (1.5-5A) and 20V (3-5A). It's fairly easy to imagine 48V between rooms and then a converter in the sockets able to provide USB voltages. You wouldn't want to run a heater or a vacuum cleaner from it, but it would be nice for a lot of consumer electronics.

We're not talking grid back-haul though, we're talking a few tens of metres maximum within a house. I've wondered for a while if it would be more efficient to have moderately high voltage DC room-to-room and then low-voltage DC in rooms. Given the number of things in my house that would prefer a DC supply and so end up with (cheap and inefficient) AC to DC convertors per plug (and especially if you use LED lighting), it seems like it ought to be a win. And now seems like a good time to do it, as USB-C is a consumer connector that can provide up to 100W via something that's designed to be very cheap to produce in the lower power variations.

Top 10% probably. Take a look at a global rich list calculator. You can live very comfortably in a western country with 9% of the world's population being richer than you. If you're in some parts of central or eastern Europe, or a few parts of south-east Asia then you may be near the bottom of the top 20% and still living very comfortably. The '1%' that people talk about in the USA are well in the top 0.1% globally, but 'the 1%' makes a better soundbite than 'the 0.1%'.

Fewer seamen suffer from PTSD than VB coders.

I find it hard to consider anyone who owns a house (even with a mortgage), especially in one of the places with the highest property prices in the world, poor. This scheme seems very odd, because the poorest residents of California are renting, they don't own houses (well, the poorest are homeless), who can't just stick solar panels on top of a house that they're renting.

Apple used to ship iSync with OS X, which could sync calendars and contacts with a wide variety of phones via bluetooth or a cable. It also had a nice plug-in architecture for adding new sync clients (and new kinds of data to sync). They also had some Bluetooth integration with the address book app, so when someone called your phone you'd get a pop-up on the screen of who it was and could send SMS directly from the address book. All of these features disappeared with the first OS X release after the iPhone and were replaced with cloud-base syncing that only worked with the iPhone.

Online copies are just RAID done at the file level instead of the block level. The reason that RAID is not considered a substitute for a backup is that user error or a compromise can damage all online storage. If your backups are online, they are not backups, they're just redundancy.

There were a few things (GDI handles and suchlike) that had very small limits. Once you exhausted them, the system was basically unusable. There was a little program you could run that would show the number allocated vs allowed. By the time you'd launched one program, they were normally 60-90% gone.

These two are related. OS/2 needed 16MB of RAM to be useable back when I had a 386 that couldn't take more than 5MB (1MB soldered onto the board, 4x1MB matched SIMMs). Windows NT had the same problem - NT4 needed 32MB as an absolute minimum when Windows 95 could happily run in 16 and unhappily run in 8 (and allegedly run in 4MB, but I tried that once and it really wasn't a good idea). The advantage that Windows NT had was that it used pretty much the same APIs as Windows 95 (except DirectX, until later), so the kinds of users who were willing to pay the extra costs could still run the same programs as the ones that weren't.

I never ran 3.0 on a 386 to try that. On Windows 3.1 it wouldn't work, because the OS required either (286) protected mode or (386) enhanced mode. Running 3.0 on a 386, the DOS prompt would use VM86 mode (yes, x86 has had virtualisation support for a long time, but only for 16-bit programs). Windows 3.0 could run in real mode, so would work inside VM86 mode. In real mode, it didn't have access to VM86 mode (no nested virtualisation), so probably couldn't start again.

I'm not sure if it ever became a real product, but the Novell guys did have Netware running as a paravirtualised Xen guest. Apparently it was quite an interesting challenge, as Netware was one of the few operating systems to use rings 1 and 2 on i386.

And Windows 3.1 lost real mode support. You could run Windows 3.0 on an 8086 with an EGA screen and 640KB of RAM (I did - the machine originally shipped with GEM). I think 3.1 still have 286 protected mode support, but didn't work very well unless you ran it in 386 enhanced mode. It was a bit sad that the version of Windows that required an MMU didn't use it to implement memory protection...

Sort of. The desire not to cannibalise sales was a key factor in the design of the PC, but these were also features that IBM didn't think would be missed.

IBM knew what multitasking was for: it was to allow multiple users to use the same computer with administrator-controled priorities. Protected memory was for the same things. Why would you need these on a computer that was intended for a single user to use? A single user can obviously only run one program at a time (they only have one set of eyes and hands) and you can save a lot in hardware (and software) if you remove the ability to do more. And, of course, then no one will start buying the cheap PCs and hooking them up to a load of terminals rather than buying a minicomputer or mainframe.

My father's company got their first Windows 3.0 install because they bought a diagram tool (Meta Design, I think), that came with a free copy. The company that made it had decided that bundling a copy of Windows 3.0 was cheaper than writing (or licensing) a graphical toolkit for DOS and an associated set of printer drivers. I don't know if they were the only company to do this, but after a year or so they stopped bundling Windows and just expected their customers to either have a copy already or go and buy one.