CONTROL CONTEXT CONVERT
CONTROL word ( -- val )  
smart-word <FORTH-83-L&P>
see ASCII, but returns char - '@'
 simulate:
   : CONTROL  [COMPILE] [CHAR]  [CHAR] @ -  
              STATE @ IF [COMPILE] LITERAL THEN ;

reference: p4_control in ../src/lpf83.c:0306, export CS CONTROL