"In a previous message, Simon J DeBoer wrote:"
> 
> as: /var/tmp/cc001106.s:1061: Error: Unknown pseudo-op:  `.weak'
> make[2]: *** [SLList.o] Error 1
> 
> Is this just that I don't have the most recent version of gas ??

It works for me.  Here's my as version:
GNU assembler version 1.92.3, NetBSD $Revision: 1.3 $

Also, make sure you are using the nes gcc to compile that.  I took my old
cc, gcc, c++, g++ and moved them to a backup place.

Mark