On Fri, 18 Feb 2022, Paul Koning via cctalk wrote:
From what was just reported, the 6000 series indeed
did it that way.
But I think on the 9000 it was an I/O bus too. I definitely remember
some work on XMI based I/O devices, in particular an FDDI card. And
indeed you can find a spec for that device in
http://www.bitsavers.org/pdf/dec/xmi/ .
Also:
<ftp://ftp.linux-mips.org/pub/linux/mips/people/macro/DEC/DTJ/DTJ305/DTJ305PF.PDF>.
Maciej