Procedure TLON(	Log_nam: Packed array [lo..hi:Integer] of char;
		VAR Equ_str: Packed array [elo..ehi:Integer] of char;
	        VAR Equ_length: Integer
	);
   EXTERNAL;
{*USER*
 Pascal-3 procedure to translate a logical name. Identical to Rlon,
but only performs one translation.
 Log_nam and Equ_str are conformant string parameters.
Equ_length will always return the actual equivalence string length, even if
greater than that allowed by Equ_str. Equ_str would in this case be filled
with as much of the equivalence string as possible.
 Equ_length (and the length byte of a type-0 Equ_str actual parameter) will
be zero if the logical name is not found.
 
 Directive Status is available in $DSW on return.
}