> +AIX)
The 4 and 5 should not be required if you use the bootinfo command like the following:
AIX)
	MACHINE_ARCH=`bootinfo -T`
esac
The bootinfo command is supported in AIX 3,4, and 5. If you use it, we get AIX 3 support for free.
This would also eliminate the incompatibilty between pkgsrc packages in AIX 4 and 5. The added bonus is
that a package compiled(correctly), the resultant binaries would be transferrable between the RS/6000
and later POWER chips. 
This would very nice for us who still use AIX 3 on a daily basis and don't want to wait for hell to 
freeze over for binaries to compile on older machines.
-Andy Wallis