Adjust this for your system.

~~~
:MS (n-)  #2000 * [ ] times ;
~~~

Ported from http://thecutecuttlefish.org/tmp/morse.fth

~~~
'SPEAKER var

:START-SOUND (--)
  './dev_dsp file:W file:open !SPEAKER ;

:STOP-SOUND (--)
  @SPEAKER file:close ;

:BEEP (cycles--)
  START-SOUND
  [ '----**** [ @SPEAKER file:write ] s:for-each ] times
  STOP-SOUND
;


:- #45 c:put #500 BEEP #50 MS  ; (Long
:. #46 c:put #100 BEEP #10 MS  ; (Short

:P  #50 MS      ; (Pause
:LP #500 MS sp  ; (Long_Pause

:A? dup $A eq? [ . - P     ] if ;
:B? dup $B eq? [ - . . . P ] if ;
:C? dup $C eq? [ - . - . P ] if ;
:D? dup $D eq? [ - . . P   ] if ;
:E? dup $E eq? [ . P       ] if ;
:F? dup $F eq? [ . . - . P ] if ;
:G? dup $G eq? [ - - . P   ] if ;
:H? dup $H eq? [ . . . . P ] if ;
:I? dup $I eq? [ . . P     ] if ;
:J? dup $J eq? [ . - - - P ] if ;
:K? dup $K eq? [ - . - P   ] if ;
:L? dup $L eq? [ . - . . P ] if ;
:M? dup $M eq? [ - - P     ] if ;
:N? dup $N eq? [ - . P     ] if ;
:O? dup $O eq? [ - - - P   ] if ;
:P? dup $P eq? [ . - - . P ] if ;
:Q? dup $Q eq? [ - - . - P ] if ;
:R? dup $R eq? [ . - . P   ] if ;
:S? dup $S eq? [ . . . P   ] if ;
:T? dup $T eq? [ - P       ] if ;
:U? dup $U eq? [ . . - P   ] if ;
:V? dup $V eq? [ . . . - P ] if ;
:W? dup $W eq? [ . - - P   ] if ;
:X? dup $X eq? [ - . . - P ] if ;
:Y? dup $Y eq? [ - . - - P ] if ;
:Z? dup $Z eq? [ - - . . P ] if ;

:SP? dup #32 eq? [ LP ] if ;

:1? dup $1 eq? [ . - - - - P ] if ;
:2? dup $2 eq? [ . . - - - P ] if ;
:3? dup $3 eq? [ . . . - - P ] if ;
:4? dup $4 eq? [ . . . . - P ] if ;
:5? dup $5 eq? [ . . . . . P ] if ;
:6? dup $6 eq? [ - . . . . P ] if ;
:7? dup $7 eq? [ - - . . . P ] if ;
:8? dup $8 eq? [ - - - . . P ] if ;
:9? dup $9 eq? [ - - - - . P ] if ;
:0? dup $0 eq? [ - - - - - P ] if ;


:MORSE (s--)
  nl
  [
    A?
    B?
    C?
    D?
    E?
    F?
    G?
    H?
    I?
    J?
    K?
    L?
    M?
    N?
    O?
    P?
    Q?
    R?
    S?
    T?
    U?
    V?
    W?
    X?
    Y?
    Z?
    
    SP?

    1?
    2?
    3?
    4?
    5?
    6?
    7?
    8?
    9?
    0? drop ] s:for-each
;
~~~

A simple test case:

```
'SOS_OR_NOT MORSE
```