adds multiplication

without overflow testing, like the others

lib/risc/boot.rb

@@ -184,7 +184,7 @@ module Risc
       end
 
       obj = space.get_class_by_name(:Integer)
-      [ :putint, :mod4, :div10, :+ , :-].each do |f|   #mod4 is just a forward declaration
+      [ :putint, :mod4, :div10, :+ , :- , :*].each do |f|   #mod4 is just a forward declaration
         obj.instance_type.add_method Builtin::Integer.send(f , nil)
       end
     end

lib/risc/builtin/integer.rb

@@ -23,6 +23,9 @@ module Risc
           compiler.add_mom( Mom::ReturnSequence.new)
           return compiler.method
         end
+        def *( context )
+          operator_method( "mult" , :*)
+        end
         def +( context )
           operator_method( "plus" , :+)
         end