There's a surprising amount of good info here about very first IRISes. I ended up with 3 of the very first IRIS 1400 workstations mentioned in the post which NASA Ames bought; at least one of which is still in working order. They were my first unix workstations (running a Unisoft-based sysv/bsd hybrid pre-IRIX variant), and is where I first learnt UNIX, C, IRIS GL, vi and lots of other good stuff. Irritatingly they shipped with an XNS rather than TCP/IP network stack (although I did get hold of a beta IP stack, I never got it work). I did get XNS working on a LAN using their EXOS 101 ethernet cards tho.
In case anyone's interested, their graphics card (GE1, the world's first ever hardware 3D graphics card?) looks like:
https://matrix-client.matrix.org/_matrix/media/v3/download/m...
...and the PM2 68k processor card mentioned in the post looks like:
https://matrix-client.matrix.org/_matrix/media/v3/download/m...
...and one of the machines itself looks like:
https://matrix-client.matrix.org/_matrix/media/v3/download/m...
Suffice it to say that I have a very soft spot for these machines :)