anchor.diff:      then
     key? until ;
   
  -: rf69. ( -- )  \ print out all the RF69 registers
  +: rf. ( -- )  \ print out all the RF69 registers
     cr 4 spaces  base @ hex  16 0 do space i . loop  base !
     $60 $00 do
       cr
  
positive.code:    0 variable rf.afc
    66 buffer:  rf.buf
  
  8683 variable rf69.freq
    42 variable rf69.group
    61 variable rf69.nodeid
  
  create rf:init  \ initialise the radio, each 16-bit word is <reg#,val>
  hex
    0200 h, 0302 h, 048A h, 0505 h, 06C3 h, 0B20 h, 1942 h, 1A42 h,
    1E0C h, 2607 h, 29C4 h, 2D05 h, 2E88 h, 2F2D h, 302A h, 37D0 h,
    3842 h, 3C8F h, 3D12 h, 6F20 h, 7102 h, 0 h,  \ sentinel
  decimal align
  
  \ r/w access to the RF registers
  
negative.code:   ( u ) dup 10 rshift  RF:FRF rf!
    ( u ) dup 2 rshift  RF:FRF 1+ rf!
    ( u ) 6 lshift RF:FRF 2+ rf!
    ;
  
  : rf-group ( u -- ) RF:SYN2 rf! ;  \ set the net group (1..250)
  
  