= Hex input mode

        XIN

            -exchange Hex digit input mode and normal input mode.
             default function key is Ctrl+F11.
            -After entered Hex input mode,"x" appear at top-left corner.
            -Hex digit input is accepted on the area file lines displayed.
            -Char is transferred to cursor pos at end of 2byte input
             for DBCS,but by "x" key only 1st byte of DBCS is transferred.
             But for binary file,No DBCS check is done,and Input-inhibit-
             char check is not done.
             For EBCDIC file, it will be sent byte by byte.

            -"u" and "v" key is for unicode input.
             "u" key start UCS2 input and "v" key start UCS4 input.
             Remaining premature hex code is transferred to file text area by also
             "u" or "v" key.
             "u" or "v" is required to each unicode char.

            -Command input line accept UTF8 code by this HexInputMode.
             When started by "u" or "v", unicode is translated to UTF8 code.
             Without "u" or "v", the char itself is sent.
             To input "u" or "v" itself, duplicate it.
             UTF8 code is accepted at command input line, dirlist rename input field,
             FileNameList panel(=1, =2) and Utility panel(=3.12, =3.14).