Binary Compatability?

[Mike Muuss]

I had heard a rumor that IRIX 3.1 was supposed to produce binary executable
programs that would run unchanged on all the different kinds of 4D machines
(assuming that the program was adroit enough to avoid hardware-specific
routines on machines that could not do them).

Is this true in all cases?  Is this true only when using the "shared" versions
of the libraries?  Or is my understanding in error?

In my particular case, I compiled a program on a GTX, and tried to run
the binary that worked fine on the GTX on a Personal Iris (via NFS).
I got the message:

Unable to map GM DRAM: No such device

Clearly, the Personal Iris does not have a GM, so something odd is happening.
Anyone care to share some clues?
	Best,
	 -Mike