6.1.0898
CHARS
chars
CORE
 
( n1 -- n2 )

n2 is the size in address units of n1 characters.

Testing:
( CHARACTERS >= 1 AU, <= SIZE OF CELL, >= 8 BITS )
T{ 1 CHARS 1 <       -> <FALSE> }T
T{ 1 CHARS 1 CELLS > -> <FALSE> }T
( TBD: HOW TO FIND NUMBER OF BITS? )