Facts - (Maybe not as I got these mainly from usenet, so they might not be entirely accurate)
 

• NT cannot be installed on non-PCI PowerPC machines.
• NT can be installed on these machines
• PowerStack RISC PC (Motorola)?

The CPU is MPC604, firmware is PPC1bug
Visit this page for boot software. IBM ARCBootloader will not work on Motorola.
http://www.mot.com/GSS/MCG/support/soft/Firmware/mfwupgrade.html
• RS/6000 40P
• RS/6000 43P
• RS/6000 Notebooks
• RS/6000 860 - Thanks to Andrew Chen for the info!
• IBM Power Series 820
• IBM Power Series 850
• NT cannot be installed on these machines
• RS/6000 250
• This is definitely accurate - Microsoft has dropped all support for NT on PowerPC, the latest and LAST update is Windows NT 4.0 Service Pack 2, which can be downloaded from Microsoft's Web site.

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