[jpstewart]

I do not understand about your explanation.
I try to format and partition with "fx" for example;
boot -f dksc(0,1,8)sashARCS

Right here you're trying to boot from the newly-created emulated disk:  dksc(0,1,8) means disk at controller 0, ID1, partition 8.  You've previously said that ID1 is the emulated disk.  You cannot boot from it at this point;  it is blank.  There is no partition 8 yet.  There is sashARCS on it yet, since you haven't installed IRIX yet.

You need to boot from another source -- an installation CD or a network install source -- and run fx from there.  Then you can create the partition(s) and so on.  (This is instead of your step 7 from the list.)

The other problem is you're trying to load sashARCS;  that's not the same as fx.

There are many guides to installing IRIX.  Read one and follow it.  Your SCSI2SD is correctly set up and configured as a blank disk.  So partition it with fx and install software to it before trying to load sashARCS or anything else from it.  At this point you can forget about the fact that it is a SCSI2SD setup and proceed with installing the operating system as you would with a real disk.