Risc/6000 uname -m and cpp predefined identifiers

[Wendy Ross]

uname -m
on any DecStation 5000 yields: MIPS
on any Sun yields: sun3 sun4 sun4c, etc.
on any Apollo DN3500 yields: DN3500
                 
on any RS/6000 yields a number which is unique to the machine
(corresponds to a chip number was the rumor)
    
Is there an alternate command under AIX3 which is analogous to what is normally
expected from uname -m?
Mere curiosity also prompts me to wonder why this was done in the first place?


Anyhow, the second question is regarding cpp:
Are there any predefined identifiers that (either) cpp will recognize, so that
I can #ifdef code specific to the architecture without have to cc -D<some identifier>?
                                    
I noticed that many X include files want AIXV3 defined, and imake was set up
to deal with this (although it is not predefined by either cpp).  

Thanks for any help; please mail directly and I'll summarize.
 
Wendy

Internet: wross at caen.engin.umich.edu
<insert amusing quip here>