AIX 4.1.5 will only run on RS/6000s. There is
an older version of AIX which is nolonger available,
that used to run on IBM PS/2's, called PS2/AIX. This product was discontinued in the early 90's.
recently, IBM annouced a new Linux Affinity program that
indicated that AIX version 5L would possibly run on Intel Itanium Processors. I do not know where this stands today.