|This post is quite old, but since it hasn't been locked, I think I'll add to it for people browsing this thread in the future:|
@Jnewman, why couldn't you install SP6a on it? Stanford University has Service Pack 3, 4, 5, and 6 available on their FTP (ftp://ftp.cs.stanford.edu/pub/Windows/NT-Stuff/, and I have all the packs going back to SP1 available on my site (http://sdfox7.com/winntsp.htm)
Regarding availability, NT 4.0 is available on eBay, brand-new still in the shrinkwrap, and this is a perfectly legal method of obtaining it.
iMac G5 1.8GHz "Hero" PowerPC
2 x 1GB DDR PC3200 SDRAM
160GB WDC WD1600JD-40GBB2
Mac OS X Leopard Version 10.5.8