A/UX runs on 68k NuBus machines, not PowerPC PCI ones.

Unix itself does—seems like a short porting effort compared to the other choices. They had emulation available as well.

A/UX 4.0 I believe was going to be based on OSF/1. The MkLinux port was also useful in the Mach 3.0 migration (as were the open source BSDs which refreshed the 4.4BSD code Rhapsody was based on, from NEXTSTEP 4.0 which only ever shipped as an alpha).

A/UX was still a licensed version of Unix. This post says the licensing fee was $1,000 per seat.

https://www.reddit.com/r/Apple_AUX/comments/11wks6i/what_was...

I remember the AT&T / BSD lawsuit in 1992. Maybe Apple looked at NeXTSTEP and since it is based on the Mach microkernel and BSD that they would be able to fix the 10 or so files to avoid the AT&T / Unix System Labs licensing fees like Free/NetBSD did.

In the 1980's Microsoft had their own port of Unix named Xenix. Why didn't they push this instead of the very limited MS-DOS?

https://www.abortretry.fail/p/the-history-of-xenix

> In March of 1982, Western Electric reduced the royalty fees that it charged for UNIX with the introduction of UNIX System III (a combination of UNIX V7 and PWD). This was done by raising the source license cost, but lowering the royalty per user license to $100 (about $318 in 2023) from $250. This meant that Microsoft’s prepayment of $200000 in 1980 (around $700k in 2023) for a discount in volume was voided if they wished to use the newer system. That same month, on the 10th, Paul Allen held a seminar in NYC where he outlined plans for MS-DOS 2.0.

> Why didn't they push this instead of the very limited MS-DOS?

Hardware requirements.

For a (quite long) while the plan was to keep DOS for microcomputers and Xenix for the serious stuff. DOS gained some extensions that made it very Xenix/UNIX-like (like subdirectories, pipes, "-" as command line switch char, device files in "\dev" instead of a global namespace, etc.).

I think for the time period, hobbyists can't be written off either. My dad got into Commodore and Atari in the late 70's/early 80's, and sparked my interest in software. Computing already wasn't cheap, but if the home consumer needed to pay for extra licensing fees, I could easily see adoption being far more limited to business. I think a lot of developers, myself included, got their start as hobbyists and never would have caught the "itch" to develop if for not this early exposure at home.

While MSDOS had subdirectories, pipes were not supported at the kernel level. It was simply a convenience of COMMAND.COM that simulated pipes by running each command sequentially. The command switch character was the slash (/) until the end, with the exception of a few non-standard third-party softwares insisting on the dash. Device names were always global namespace and \dev never existed in any form.

Did you copy-paste an hallucinating LLM?

No, it looks fair.

MS-DOS 1.x did not have subdirectories.

That came in with MS-DOS 2.x which is when the very rudimentary level of Xenix compatibility came in: device names such as `LPT1:` or `COM2:` could be prefixed as `/dev/lpt1` or `/dev/com2`. Pipes simulated in COMMAND.COM.

I don't recall DOS ever accepting command switches prefixed with `-` instead of `\` as standard, though.

The features were never turned on by default, so they are not popular knowledge (I used DOS since 2.x and never knew).

https://forum.winworldpc.com/discussion/comment/171783/#Comm... (devices in \dev, "-" as switch char, etc.).

> While MSDOS had subdirectories, pipes were not supported at the kernel level. It was simply a convenience of COMMAND.COM that simulated pipes by running each command sequentially.

You are confusing the lack of concurrency with lack of pipes -- the mere fact that COMMAND can do what you describe requires UNIX-like pipes and channels (e.g. stdin/out/err), and programs avoiding direct console I/O (way common for DOS programs...). Comm software such as Kermit did the same thing to simulate remote login (I used this one in the day, at least).

Hmm I remember switches always had to begin with “/“ in DOS

Yep, that must have been it. Porting it to BSD might have been more work and opened them up for a lawsuit.

How was Solaris an option then?

Good question but I don't know.

Apple did not create A/UX. It was created by UniSoft

https://en.wikipedia.org/wiki/UniSoft

https://virtuallyfun.com/2021/09/19/so-what-is-the-deal-with...

I'm guessing that Apple would have to pay a fee to both UniSoft and AT&T and maybe Sun was much larger and a partner with AT&T / Unix System Labs on SysV so maybe they could resell Solaris for cheaper.

Sun open sourced Solaris in 2008 for 2 years. Maybe AT&T / USL didn't care by then or maybe Sun's licensing agreement allowed them to do it. I don't know.

A/UX was also ridiculously insecure in its default configuration. It had a "guest" user, no password. I remember labs of Mac II or IIx systems at a local university, with public IP addresses, guest accounts, no passwords. A local BBS guy posted a message on how to get "free" internet access through the university's dialups. I think it was at least a month before things got locked down.

It was the time, only trustworthy people on the net so far. Told the story here about my mid-ninties job where I ran Quake servers on the lan before we had a firewall.

Yes, though contemporary OSes like SunOS were more secure than A/UX. Once you were on the network though, it was like swiss cheese (NIS / YP... unshadowed password files... etc.)

Interesting what-ifs. Perhaps offering the money they spent on Copeland to ATT could have bulk licensed it.

> Why was A/UX not in the running?

I asked this myself.

The thing that I didn't think about was that A/UX combined 680x0 UNIX™ code with 680x0 MacOS code in very clever ways. MacOS provided the windowing, terminal emulators, the filesystem browser, etc. Unix provided the underlying kernel, the filesystem, networking, etc.

(This is a hand-wavey simplification for illustrative purposes.)

The point being, intimately intertwined, closely integrated.

But classic MacOS only ran on 680x0 and to port it to PowerPC, Apple invented a clever hack built around partial emulation: a nanokernel containing a 680x0-to-PowerPC interpreter (with a way for 680x0 code to call PowerPC code), on top of which ran the MacOS Toolbox ROM image, on top of which ran most of MacOS in 680x0 code. Then they profiled that, and converted the most performance-critical parts -- and only those -- to PowerPC code.

When I ran a PowerMac with classic MacOS, I had a little indicator applet in the menu bar. It was red when executing 680x0 code and turned green for PowerPC code. (Not very helpful for colour blind folks, but hey, fine for me.)

It was red almost all the time. Only years later when substantial PowerPC-native apps started to appear did it sometimes stay green long enough to see.

It wouldn't have been so hard to port the Unix bits of A/UX to PowerPC-native, but that would have ruined the integration between the Unix code and the MacOS code. Getting MacOS all running natively would have been a massive task. Apple never did it; it replaced the entire OS with NeXTstep.

Getting 680x0 MacOS code integrating with PowerPC A/UX code would have been a major technical challenge.

It sounded easy and obvious but it was an even bigger project than Copland, and Apple wisely dediced against it.

Interesting, and sounds quite plausible. Perhaps they could have replaced the GUI with a X window lookalike instead of trying to brute force the old OS.

That is what the Apple/NeXT combined company did, of course. Rhapsody showed it well.

http://toastytech.com/guis/rhap.html

And there's some description of the emulation nanokernel:

https://en.wikipedia.org/wiki/Mac_OS_nanokernel

But in its way OS X was much more of a clean break: a whole new OS, ported to the old hardware, tweaked to understand filesystems and file formats and given a shallow cosmetic resemblance.

A/UX was a much tighter integrated system. Some of the OS functionality was provided by actual classic MacOS.

What was left, if that was removed, was a fairly unremarkable Unix for its time. You could even boot it in a sort of vanilla-Unix form.

You can compare and contrast here:

https://www.aux-penelope.com/screenshots.htm

E.g. for v3, top 2 rows (pics 1-6) are in Mac mode, bottom row (7-9) are in Unix mode. A bit like the ANS with AIX, there's little to appeal to Apple users here:

https://www.floodgap.com/retrobits/ans/aix.html