Developer ports Windows NT to Power Macintosh systems — firmware and boot loader now available

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It's not stable, but it will boot and run ... most of the time.

Old PowerBook keyboard
(Image credit: © Raimond Spekking / CC BY-SA 4.0 (via Wikimedia Commons))

There might be a new use if you’ve got an old Power PC-based Power Macintosh. A developer has successfully ported Windows NT 4.0 to the Power Macintosh and published the firmware and other software needed for it to work. Thanks to one skilled developer, that’s changed. On GitHub, contributor Wack0 recently released his maciNtosh project, a repository that includes the ARC firmware and its loader.

While Microsoft did port Windows NT 4.0 to the PowerPC years ago, the Power Macintosh doesn’t use the same firmware needed for Windows NT. The PowerPC version of Windows NT only supported IBM and Motorola systems using PowerPC. Support for the more popular PowerPC computers from Apple never surfaced.

The so-called New World Power Macintosh systems used the MPC106 “Grackle” memory controller and PCI host and either the “Heathrow” or “Paddington” super-I/O chip on the PCI bus. That means if you have one of the following Power Macintosh computers, you can use the repository to install Windows NT 4.0:

  • iMac G3 (tray-loading)
  • Power Macintosh G3 (blue and white, “Yosemite”)
  • Macintosh PowerBook G3 with the bronze keyboard (“Lombard”)
  • Power Macintosh G4 PCI (“Yikes!”)

The author says the ARC firmware should also run on Old World systems like the beige Power Macintosh G3 and the Macintosh PowerBook G3 Series (“Wallstreet” and “PDQ.”) However, there isn’t a boot loader yet for those systems.

(Image credit: Virtually Fun)

Wack0 also acknowledges that the project is very experimental, having only tested on Lombard systems. Furthermore, some drivers, such as the Cuda driver, have yet to be tested on real hardware. Also, the loader only supports ATI graphics chipsets, and ATI hardware with a fcode version before 1.69 might pose problems.

Installing Windows NT on your Power Macintosh requires the firmware and loader from the GitHub repository, along with Windows NT 4.0 installation media. Fortunately, a simple Google search makes disc images easy to find. Wack0 provides detailed, step-by-step instructions to get Windows NT up and running.

It is an exciting project, and it makes me wish I still owned the PowerMac G4 I used to have. Of course, don’t expect stability, at least not yet. The author has developed the drivers just enough to run and use NT and notes that there are occasional PMU hard shutdowns when booting.

Jeff Butts
Jeff Butts
Contributing Writer

Jeff Butts has been covering tech news for more than a decade, and his IT experience predates the internet. Yes, he remembers when 9600 baud was “fast.” He especially enjoys covering DIY and Maker topics, along with anything on the bleeding edge of technology.

2 Comments Comment from the forums
  • bit_user
    IMO, Linux would be a better use for them. You can actually buy much more recent POWER (desktop) machines, for running Linux.
    https://raptorcs.com/
    Back in 2018, they were the first to support PCIe 4.0. Nowadays, they're getting a bit long in the tooth.

    Anyway, one thing I wonder about WinNT on PPC is whether it ran in Big Endian or Little Endian mode. I'm pretty sure PowerPC was bi-endian, enabling it to support either. These days, most people running Linux on POWER seem to use Little Endian. As that matches Intel, you probably run into much fewer issues, that way.
    Reply
  • Stesmi
    Most were bi-endian, as you point out, and Windows NT 4 ran in little endian mode. A register in the MSR sets the mode.
    Reply