Yep - I knew I'd rue the day I got rid of my old SCSI gear when shifting house!
Anyone have an old (probably caddy) SCSI CDROM (Toshiba 3401[B|E] is good apparently) that may work in an SGI box circa 1993-1995?
I had tracked down an Ex-IBM RS6000 one, but it was dated 1996 and whilst seen as a device on the SCSI bus, was not recognised by the OS (possibly something to do with block sizes specific to the SGI which can be tweaked on the Toshiba models).
I'll try popping into Molten media on the off chance, and might be able to do something with an old Pioneer 6 stacker if I can get the right cable. Then again, the root cause may be a slightly knobbled OS (which I am trying to fix be reinstalling from CD) which may not have an understanding of ISO9660.
Other than that I'll have to try and extract the IRIX .iso images and load them via a RaspberryPi over the ethernet. Makes sense, a US$40K workstation being resurrected by at $40 Linux box!