hex editor letter case changing?

The above poster is right only if your text file is using ASCII or UTF-16 (in some restricted cases). Otherwise he is wrong.

This is the general answer:

Figure out which character set and encoding is being used. If the character size is fixed (e.g. 16 bits) then it's pretty straightforward - scan every group of 16 bits, if that group represents a lowercase letter then you have to add/subtract (depending on the character set) some fixed amount.

If you're dealing with a dynamic sized encoding (e.g. UTF-16) then you need to study that encoding's official specification.

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By the way, the poster said "20h" that is NOT a twenty. You obviously are not friendly with binary/hex in which case you should stay away from hex editors. They are not made for you.

If I understand what your saying top Case letters are > A, B, C < top case Definition - between the vast alphabetic characters used with the aid of fact the 1st letter in writing or printing appropriate names and in specific circumstances for emphasis; "printers as quickly as saved the type for capitals and for small letters in separate circumstances; capitals have been saved in the top 0.5 of the type case and so became everyday as top-case letters" decrease Case letters > a, b, c < decrease case Definition - elating to small (no longer capitalized) letters that have been saved in the decrease 0.5 of a compositor's type case; "lowercase letters; a and b and c etc"

Subtract 20h from all characters between 61h and 7Ah.