Are you counting the notes, or the intervals? Are you counting the root once or twice (1 and 8)? Got fencepost errors?

I end up dealing with this a bit more, because I play mountain dulcimer, and dulcimer tab notation starts at 0 instead of 1, counting from the open strings to N frets in a mostly-diatonic scale. (Usually the tuning on the middle string means you end up with at least one more note available, plus most dulcimers these days add the 6.5 fret (which gets you the 7th note in the melody string's scale, as opposed to a flat-7th Mixolydian), which gives you a few more choices.

LAN Manager might have hacked something over the top, but OS/2 was fundamentally a single-user OS, no different to DOS or MacOS.

My understanding is that NT had quite a bit of OS/2 in it.

It doesn't. They are completely different architecturally. NT was a 32-bit, multiuser, heavily multithreaded, built-for-SMP, portable, mostly-microkernel OS.

OS/2 was... Not.

Seeing that MS had rights to OS/2 and wanted a new OS in a hurry following the breakdown of their partnership with IBM, it would be suprising if they had not used parts of OS/2.

In a hurry ? It was five years between the start of NT's development ('88) and its first release ('93).

LAN Manager was multiuser. The client wasn't but that doesn't make much difference as the non-multiuser smartphones phones using apps and websites today proves quite well.

I see turbidostato below made the same point.

OS/2 had networking (really good networking) and multitasking. Lan Manager (based on OS/2) as well as Novell (worked with OS/2) had file permissions. So they produced a product with those 3 facets.

Seriously, the 8088/80286 and their addressing space limitations set back the DOS-based world by years, until Intel finally accepted that people wanted to use individual chunks of memory larger than 64K, and that they wanted to run their old real-mode DOS programs, too.

Intel wasn't the problem. The 386 was released in 1985.

Win 3.0 was absolutely awful. It crashed and needed a reboot about twice an hour.

Rubbish.

It was soon replaced with the improved 3.1.

It was two years between Windows 3.0 and 3.1.

One major reason for the split was that IBM insisted on programming OS/2 in assembler - over Gates' objections - locking them onto the 386 platform.
At least that is the way I remember it.

I think you are remembering IBM's insistence that OS/2 ran on their shiny new "AT", with it's 286 processor when the 386 was already out on the market.

It was already working on the next version of OS/2, but split from IBM's path and re-branded the new product as Windows NT. IBM then started their own separate development path and produced OS/2 2.0.

Minor correction. Microsoft - Dave Cutler's team - were working on the OS that was going to replace OS/2 (OS/2 "New Technology") that was then turned into Windows NT 3.1 and successors after the (surprising) Windows 3.0 success.

IBM took the "old" OS/2 code (that both they and Microsoft had worked on) and tarted it up into OS/2 2.x and successors.

Windows NT and OS/2 have no common ancestor. They are completely different OSes from bottom to top.

That explains why in the mid '80s to mid 90's IBM was busy in a joint venture with Microsoft first and alone afterwards... to produce a PC system with networking, multi-tasking and file permissions and even 32 bits (OS/2).

OS/2 (at least in that timeframe) was not multiuser. Neither was it 32-bit (IBM insisted it run on their brand-spanking new AT with its 16-bit 286 CPU).

And the Microsoft/IBM "divorce" was around 1990.

With that said I don't agree with GP. I don't think IBM had that much strategy.

Last year I was looking into getting either a Raspberry Pi or Beaglebone Black. BBB had a newer ARM rev for the CPU, so it can run more kinds of OS. But the RPi has the removable flash as its drive, so you can easily load whatever OS image you want, change OSs by switching flash chips, and if you hose it too badly you can take it out and reload, without worrying about whether you've bricked the board. Also, the specs at the time said the RPi had a better GPU, and could do 1080p at 60 Hz vs. only 30Hz for BBB, which means I can plug it into TVs and monitors without as much flicker. I chose the RPi.

BBB nominally costs a bit more, but by the time you buy cases and power supplies and flash and such, it pretty much balances out.

Nice to see somebody getting it right.

b.

Congratulations, you get the job!!