procedure addCrc16(var crc: Integer; ch: Char);
const
  crc16tab: array [0 .. 255] of Integer = ($0, $1189, $2312, $329B, $4624,
    $57AD, $6536, $74BF, $8C48, $9DC1, $AF5A, $BED3, $CA6C, $DBE5, $E97E, $F8F7,
    $1081, $108, $3393, $221A, $56A5, $472C, $75B7, $643E, $9CC9, $8D40, $BFDB,
    $AE52, $DAED, $CB64, $F9FF, $E876, $2102, $308B, $210, $1399, $6726, $76AF,
    $4434, $55BD, $AD4A, $BCC3, $8E58, $9FD1, $EB6E, $FAE7, $C87C, $D9F5, $3183,
    $200A, $1291, $318, $77A7, $662E, $54B5, $453C, $BDCB, $AC42, $9ED9, $8F50,
    $FBEF, $EA66, $D8FD, $C974, $4204, $538D, $6116, $709F, $420, $15A9, $2732,
    $36BB, $CE4C, $DFC5, $ED5E, $FCD7, $8868, $99E1, $AB7A, $BAF3, $5285, $430C,
    $7197, $601E, $14A1, $528, $37B3, $263A, $DECD, $CF44, $FDDF, $EC56, $98E9,
    $8960, $BBFB, $AA72, $6306, $728F, $4014, $519D, $2522, $34AB, $630, $17B9,
    $EF4E, $FEC7, $CC5C, $DDD5, $A96A, $B8E3, $8A78, $9BF1, $7387, $620E, $5095,
    $411C, $35A3, $242A, $16B1, $738, $FFCF, $EE46, $DCDD, $CD54, $B9EB, $A862,
    $9AF9, $8B70, $8408, $9581, $A71A, $B693, $C22C, $D3A5, $E13E, $F0B7, $840,
    $19C9, $2B52, $3ADB, $4E64, $5FED, $6D76, $7CFF, $9489, $8500, $B79B, $A612,
    $D2AD, $C324, $F1BF, $E036, $18C1, $948, $3BD3, $2A5A, $5EE5, $4F6C, $7DF7,
    $6C7E, $A50A, $B483, $8618, $9791, $E32E, $F2A7, $C03C, $D1B5, $2942, $38CB,
    $A50, $1BD9, $6F66, $7EEF, $4C74, $5DFD, $B58B, $A402, $9699, $8710, $F3AF,
    $E226, $D0BD, $C134, $39C3, $284A, $1AD1, $B58, $7FE7, $6E6E, $5CF5, $4D7C,
    $C60C, $D785, $E51E, $F497, $8028, $91A1, $A33A, $B2B3, $4A44, $5BCD, $6956,
    $78DF, $C60, $1DE9, $2F72, $3EFB, $D68D, $C704, $F59F, $E416, $90A9, $8120,
    $B3BB, $A232, $5AC5, $4B4C, $79D7, $685E, $1CE1, $D68, $3FF3, $2E7A, $E70E,
    $F687, $C41C, $D595, $A12A, $B0A3, $8238, $93B1, $6B46, $7ACF, $4854, $59DD,
    $2D62, $3CEB, $E70, $1FF9, $F78F, $E606, $D49D, $C514, $B1AB, $A022, $92B9,
    $8330, $7BC7, $6A4E, $58D5, $495C, $3DE3, $2C6A, $1EF1, $F78);

begin
  crc := (crc >> 8) Xor crc16tab((crc Xor CByte(Asc(ch))) And &HFF) ; <----- das hier kann ich nicht umsetzen!
end;