anchor.diff:  
   : u  $FF >mb  $E000 a ;
   
  +task: uart-task
  +
  +: uart-reader&
  +  uart-task background
  +  begin
  +    begin uart-irq-key? while uart-irq-key emit repeat
  +    stop
  +  again ;
  +
   : s1  \ show output from USART2
     uart-init 19200 uart-baud
     c
  
positive.code:   loop cr b r ;
  
  : s2  \ switch to permanent USART2 pass-through
    cr uart-init 19200 uart-baud
    c
    begin
      uart-key? if uart-key emit then
      \ break out of terminal loop when ctrl-x is seen
      key? if key ( dup 24 = if drop exit then ) uart-emit then
  \   pause
    again ;
  
  : x  RST ioc! 1 ms RST ios! ;
  
negative.code: 
  \ : z $3A6000 d s1 ;
  : z init-all s2 ;
  : zy init-all y s2 ;
  
  : ?
    cr ." v = show chip version           b = break next "
  