anchor.diff:  PA7 constant M2D
   
   : app-setup
  -  OMODE-PP LED io-mode!
  +  OMODE-PP LED io-mode!  LED ios!
     OMODE-PP M1A io-mode!
     OMODE-PP M1B io-mode!
     OMODE-PP M1C io-mode!
  
positive.code: \   reverse2
    key? until ;
  
  app-setup
  
negative.code: forgetram
  
  PC13 constant LED
  
  PB0 constant PEN
  
  PA0 constant M1A
  PA1 constant M1B
  