reversible hexdump is a hexdump/hex2bin-toolkit that dumps to a special
readable and reversible hexadecimal byte-dump,where you can not only change
bytes, but also insert or delete bytes. It has a flush-switch, where it will
output hexbytes for each single char it reads. This is especially useful for
watching output from slow devices (e.g., serial devices like mice). The
hex2bin-utility (the reverse-hexdump) not only accepts hexbytes for input,
but also double-quoted strings with most of the escape-chars known
from C and makes good attempts at undumping even hexdumps with repetition-lines
(a "*" on its own line). It's written in ANSI C. 

WWW: http://gnuwin32.sourceforge.net/packages/hextools.htm