The filename is "ApplePCI.hqx"
http://www.magma.com/store/productpdfs/drivers/files/PCI/ApplePCI.img.hqx <-also dead

http://web.archive.org/web/20101126085410/http://magma.com/store/productpdfs/drivers/files/PCI/ApplePCI.img.hqx
^ works

the post here:
https://groups.google.com/forum/#!topic/macos9/7drB2JtNKs8
reading his interpretation he seems to think u can keep your multiprocessors enabled if u add this extension??

I have just acquired a Digidesign AudioMedia III PCI card and the Pro
Tools software to go with it. I am hoping to use this setup with a
dual processor 1.25 GHz G4 MDD, but there is a problem. According to
the Avid/Digidesign website, if you try to use this setup with a dual
processor G4 you are likely to experience -6402 errors unless the
Multiprocessor folder is removed from the Extensions folder, so
disabling the second processor. That's a pain, as the extra CPU power
would obviously be a great help when working with large audio files.

<http://archive.digidesign.com/download/mp/>

The answer is an extension called ApplePCI, info about which can be
found at the above URL. Unfortunately, clicking on the 'I Accept' link
to the download is a dead end. Since there's an Apple End User Licence
attached to the above web page, it seemed reasonable to assume this
extension might be found on and be freely downloadable from Apple's
Developer site, but I couldn't locate it there or anywhere else at
Apple. Googling only turned up the above link.

So, does anybody have a copy of this extension they could send me?

Thanks in advance.

Roger