This is only a month late, but the sound driver installation went without a
hitch, precisely according to your instructions. I fired up the Indy last
night using the latest sound kernel and played an .mp3 file using mpg123.
One thing I noticed was the absence of the occasional skips I've experienced
in recent years playing CDs under IRIX 6.2. I don't know if this can be
attributed to a larger OS or my '94-vintage single-speed SGI-enabled CD
drive, but it's not something I recall happening under IRIX 5.2. (I guess
5.2 was less taxing on 32 M RAM.)
In an aside, Tux displays brilliantly at bootup on my 8-bit Newport.