anchor.diff:  	    (#b110 (list :base :bp))
   	    (#b111 (list :base :bx))))
       (if (and (= mod-bits #b00) (= r/m-bits #b110))
  -	(next-word)
  +	(peek-at-word)
   	(case r/m-bits
   	  (#b000 (+ (register :bx) (register :si)))
   	  (#b001 (+ (register :bx) (register :di)))
  
positive.code: (defmacro with-mod-r/m-byte (&body body)
    `(let* ((mod-r/m (next-instruction)) (r/m-bits (logand mod-r/m #b00000111)) (mod-bits (ash (logand mod-r/m #b11000000) -6)) (reg-bits (ash (logand mod-r/m #b00111000) -3)))
       ,@body))
  
  ;; Templates
  
  
negative.code: (defun address-for-r/m (mod-bits r/m-bits)
    (disasm-instr
        (if (and (= mod-bits #b00) (= r/m-bits #b110))
  	  (list :disp (peek-at-word))
  	  (case r/m-bits
  	    (#b000 (list :base :bx :index :si))
  	    (#b001 (list :base :bx :index :di))
  