Procedure CASTBC( asc: Packed array [lo..hi:integer] of char;
  		 Var B: packed array [LOBC..HIBC:integer] of BCD_Digit;
  		 VAR pos: Integer
  	);
   EXTERNAL;
{*USER*
 Convert ascii array to bcd. Pos = start position in ascii string.
Pos points to end of string, or terminating character on exit.
Conversion proceeds until a non-bcd character is encountered.
Leading spaces and tabs are skipped. The output string is leading
zero filled.
}