As most of you will know, Mac OS X (or Rhapsody if you count the developer releases) wasn’t Apple’s first foray into the world of UNIX. The company sold its own UNIX variant, A/UX, from 1988 to 1995, which combined a System V-based UNIX with a System 7.0.1 desktop environment and application compatibility, before it acquired NeXT and started working on Rhapsody/Mac OS X. As a sidenote, I don’t know if the application compatibility layer was related to the Macintosh Application Environment for UNIX, which I have running on my HP-UX machines.
That’s not the only time Apple dabbled with UNIX, though – Apple’s unique Apple Network Server product from 1996 also came with UNIX, but time it wasn’t one from Apple itself, but rather from its enemy-turned-friend IBM: AIX. The Network Server shipped with a slightly customised version of IBM’s AIX operating system; regular AIX straight from IBM wouldn’t work. The more things change, the more they stay the same I guess.
Since the Apple Network Server was built around a modified Power Macintosh 9500 – there’s much more to the hardware, but that’s the short of it – so you would expect the Network Server to also be able to run regular Mac OS for PowerPC, right? Apple even sold server products running plain Mac OS at the time, so it’d make sense, but nothing about Apple in the ’90s made any sense whatsoever, so no, use of plain Mac OS was locked out through the ROM. And let’s not even get started about other PowerPC operating systems of the time, like, of all things, Windows NT – something Apple supposedly demonstrated at some point.
But was that always the case?
Well, we’ve got new ROMs straight from a former Apple employee, and after flashing them to a supported ROM chip, the Apple Network Sever can now run classic Mac OS. On top of that, and even more miraculous, the Windows NT-capable ROMs have also been discovered.
I’ll give you a spoiler now: it turns out the NT ROM isn’t enough to install Windows NT by itself, even though it has some interesting attributes. Sadly this was not unexpected. But the pre-production ROM does work to boot Mac OS, albeit with apparent bugs and an injection of extra hardware. Let’s get the 700 running again (call it a Refurb Weekend) and show the process.
↫ Cameron Kaiser
While it’s great news to see that Mac OS can now be run on the Network Server, I’m personally much more interested in the story behind the Windows NT ROMs. The idea that Apple would sell a computer running Windows NT out of the box is wild to think about now, but considering the desperate state the company was in at the time, all options must’ve been on the table. Sadly, as Kaiser discovered, the Windows NT ROMs in and of themselves are not enough to run Windows NT. However, they appear to be much farther along in the development process than even the Mac OS-capable ROMs, which is fascinating.
When Jobs talked Gil Amelio into canning the ANS as well, the ROM initiative naturally went out the window with it. However, while the existing 2.0 Mac OS ROMs are only known on an unmarked development flash stick similar to mine, these final 2.26NT ROMs appear almost production-ready with fully printed labels, suggesting they had reached a very late stage of development.
↫ Cameron Kaiser
Despite not being able to boot Windows NT for PowerPC as-is, most likely because there’s no compatible ARC or HAL, Kaiser did discover a ton of interesting details, like how this ROM configures the Network Server to run in little endian mode, which is all Windows NT for PowerPC ever supported, making this the very first time a PowerPC machine did so. I’m hoping Kaiser manages to track down the necessary components to make Windows NT bootable on the ANS, as one of the most unique curiosities in Apple history.
There’s a ton more details in the article, as per usual Kaiser standards, and it’s an absolute joy to read.

Really interesting read. I believe it was an open secret that the ANS could run MacOS internally, Apple just chose to restrict it when shipped to customers. The Windows NT find was also interesting, which makes you wonder what eventualities Apple was trying to plan for.
Early on in the Rhapsody development and Darwin, you could look at the source tree and see that Apple was actively keeping x86 going along with ppc. Of course, the view in from outside the company was via Darwin, but there was definitely work going on. I remember speculating that Apple was maintaining an x86 build in parallel just in case they needed to switch CPUs or at least have some negotiating leverage with IBM. Sure enough that ended up happening years later.
A/UX (which I have running here on a Quadra 700) was an interesting project. The whole backstory as I recall was US government purchasing was going to mandate POSIX compliance. Hardware had to run a POSIX compliant operating system. There was zero chance of MacOS (or “System”) gaining that, so Unix is basically what the purchasing requirements were saying. So Apple needed a Unix in order to sell hardware to the government. Apple originally hired one of the many vendors that would port Unix to your platform and then sort of took the wheel from there. I forget the contractor (or contractors). I *think* they did the same thing to start the MAE project, but I am not sure. I am also pretty sure the same Apple business unit did A/UX and later MAE. The timeline is such that MAE is sort of a successor to A/UX (that is, you want Mac apps and Unix apps on the same system). I really hope a former Apple employee who had a hand in A/UX or MAE reads this site and could share some insight.
Between the two I liked A/UX more than MAE. Despite the hardware limitations with A/UX, the software integration felt better. There are some really interesting things in A/UX as well, like cmdo which gives Mac dialog boxes to run Unix commands (think of a dialog box giving you all the options to something like ls). I used MAE only on HP-UX and it got the job done, but I wouldn’t say it was something I would want to use daily. Of course if I only had a single system on my desk at the time, I would pick the Unix workstation.
Yes MacOS was the least POSIX compliant OS on the market. Even AmigaOS whooped their behinds (and also ran Mac software faster and in colour where available than any mac)
Apple actively explored NT as a replacement candidate for the macos classic kernel.
There were also internal ports within apple of macos classic to x86 all along.
Initial work on Rhapsody was actually on x86, not PPC. Since OpenStep had a fully working x86 port before NeXT was acquired by apple. Interestingly enough Rhapsody also used a lot of stuff from the MkLinux project, which had both PPC and x86 versions.
IMO A/UX and MAE were very different animals. One was a full blown Unix that could run natively mac apps, where as the other was basically an 68K emulator running a virtual System 7 environment (for HPUX/Solaris?)