anchor.diff:                   (S + T) band 16#3ffff
                end,
   
  -   CPUX = pop(ds,CPU),
  -   CPUY = CPUX#cpu{ t  = R
  -                  },
  -
  -   trace(?PLUS,CPUY),     
  -   {ok,CPUY};
  +   CPUX = pop(ds,CPU,R),
  +   trace(?PLUS,CPUX),     
  +   {ok,CPUX};
   
   % 16#18  dup
   exec_impl(?DUP,CPU) ->
  
positive.code: exec_impl({?CALL,Addr},CPU) ->
     P      = CPU#cpu.p,
     {ok,I} = load(CPU,Addr),
  %%   CPUX = CPU#cpu{ p  = Addr,
  %%                   r  = P,
  %%                   rs = push(RS,R),
  %%                   i  = I 
  %%		 }, 
     CPUX = push(rs,CPU),
     CPUY = CPUX#cpu{ p  = Addr,
                      r  = P,
  
negative.code:    T = CPU#cpu.t,
     case write(CPU,B,T) of 
          {ok,RAM} ->
    	      CPUX = pop(ds,CPU#cpu{ ram = RAM },CPU#cpu.s),
  	      trace(?STOREB,CPUX),
     	      {ok,CPUX};
  
  