Most of the older PROM style systems had an issue
booting from a cd drive. You can't just use any with them. Many people report that
Plextor drives are some of the best and Toshiba drive are right behind. Don't forget
also that the cd drive must be ID 4 and be set for 512 byte sectors (not 1024 or 2048). I
personally have never tried booting my crimson with my 6.5 cd's but if you just use FX
from an Irix 5.3 cd you should be fine.
Is ID 4 essential? I've read conflicting info re: required device IDs
for booting. What is the expected behavior using a different ID?