Tested in MAME 0.218 on Feb 27, 2020

This CHD file contains an installation of IRIX 5.3 and is meant to be booted in MAME.
Also included is the ROM file (indy_4610.zip) required for booting the system. That should
be placed in /MAME/roms, while irix53.chd can just be placed in the main MAME directory. 
You can find the latest MAME binaries, source code, and compilation instructions for non
Windows platforms here:

https://www.mamedev.org/release.html

This specific disk image which might be too small for some users. You can use chdman
(see MAME docs for usage) to create a larger disk image and then install IRIX yourself
using the normal method much like you would on a real Indy. The files needed for this 
are listed below and can be obtained here:

https://archive.org/details/sgi_IRIX_5.3_for_Indy_R4400_175MHz

- IRIX 5.3

To boot this image you need to open Terminal/PowerShell in the main MAME directory and
enter the command below (remove -window if you want to start in fullscreen mode). This 
will give you an emulated Indy with a 100MHz MIPS R4600, 128MB RAM, and a 24-bit XL
graphics board.

./mame64 indy_4610 -gio64_gfx xl24 -hard1 irix53.chd -window

On first boot you will need to set the Ethernet address and display mode manually through 
the PROM setup. Click on "Stop for Maintenance" and then "Command Monitor" and enter 
the commands below. You only need to do this once, or every time you reinstall MAME 
and/or delete the NVRAM settings. This is a very important step! If you don't set the Ethernet 
address you will get a kernel panic! If you don't set the monitor mode you will get graphical 
glitches that make the desktop unusable!

setenv -f eaddr 08:00:69:12:34:56

setenv monitor h