anchor.diff:  ;;;; REFERENCES:
   ;; http://www.obelisk.demon.co.uk/6502/registers.html
   ;; http://www.obelisk.demon.co.uk/6502/addressing.html
  -;; http://code.google.com/p/applepy/source/browse/trunk/processor.py
  -;; https://github.com/jaoswald/cl-comfy-6502/blob/master/6502-opcodes.lisp
  +;; http://nesdev.parodius.com/6502.txt
   
   (defstruct cpu
     "A 6502 CPU with an extra slot for tracking the cycle count/clock ticks."
  
positive.code: (defun load-image (&key (cpu (make-cpu))
                     (ram (make-array #x10000 :element-type '(unsigned-byte 8))))
    "Set *CPU* and *RAM* to CPU and RAM."
    (setf *cpu* cpu
          *ram* ram))
  
  (defun save-image ()
    "Return a list containing the current *CPU* and *RAM*."
  
negative.code:      ,@body
       ,@(when (and track-pc (> byte-count 1))
           `((incf (cpu-pc cpu) ,(1- byte-count))))
       (incf (cpu-cc cpu) ,cycle-count)
       cpu))
  
  (defmacro defopcode (name (&key (docs "") raw (track-pc t)) modes &body body)
    "Define a Generic Function NAME with DOCS if provided and instructions,
  