Generally we refer to "16-bit editor" as "hexadecimal editor", said in this way everyone shoud understand what it is used for (often used for modifying software and game programs). Hex-Ed is a ultra-tiny (even smaller than "HEdit") and powerful hexadecimal editor, though not so strong as UE (UltraEdit), but it is free and portable.
In addition, Hex-Ed has been able to complete the basic editing operations to applications with its existing functions, such as search, jump, undo and so on, almost everything needed is ready. in particular, its size is only about 80KB after decompressed.
BTW, in Hex-Ed, the edited file does not support the function of "save as" to a new file, before modifing files, remember to make a backup first!
Download URLs
(v1.01.04 Final | Homepage)