anchor.diff:  
   (defun pop-segment (seg)
     (pop-operation (segment seg)))
  +
  +(defun mov-segment-to-indirect ()
  +  (with-mod-r/m-byte
  +    (mov (segment (bits->segment reg-bits)) (indirect-address mod-bits r/m-bits t))))
  +
  +(defun mov-indirect-to-segment ()
  +  (with-mod-r/m-byte
  +    (mov (indirect-address mod-bits r/m-bits t) (segment (bits->segment reg-bits)))))
   
   ;; Flow control
   
  
positive.code: (defconstant +byte-register-to-word+ '(:al (:ax nil) :ah (:ax t) :bl (:bx nil) :bh (:bx t) :cl (:cx nil) :ch (:cx t) :dl (:dx nil) :dh (:dx t)) "Mapping from byte registers to word registers")
  (defconstant +bits-to-register+ '(:ax :cx :dx :bx :sp :bp :si :di) "Mapping from index to word register")
  (defconstant +bits-to-byte-register+ '(:al :cl :dl :bl :ah :ch :dh :bh) "Mapping from index to byte register")
  
  ;;; Constant mappings
  
  
negative.code: 
  (defun bits->byte-reg (bits)
    (elt +bits-to-byte-register+ bits))
  
  (defun bits->segment (bits)
    (elt +bits-to-segment+ bits))
  
  (defmacro default-seg-to (default &optional (current *current-segment*))
    `(if (null ,current) ,default ,current))
  