Click on the Hexadecimal item in the View menu or press Ctrl+H to switch between text and hexadecimal editing. The undo and redo lists are cleared whenever you switch.
In hexadecimal mode, the editing area is split into three zones. The left zone is a column with byte offsets. It indicates the offset relative to the start of the file of the first byte on each row in the hex editor. The first file in the byte has offset zero.
The middle area shows all the bytes in the file represented as a hexadecimal number. You can type in the numbers 0 through 9 and the letters A through F to insert bytes. To change some bytes without changing the length of the file, press the Insert key on the keyboard to toggle between Insert and Overwrite mode. In Overwrite mode, the bytes you type in will replace the bytes already present in the file.
The right hand column shows the textual representation of each byte. You can select the code page used to translate the bytes into characters in the Editor Preferences. You can type characters into the text column. EditPad Pro will use the selected code page to translate them into bytes.
If you want to see only hexadecimal representation or only the textual representation, select Hexadecimal Only or ASCII only in the submenu of the Hexadecimal item in the View menu. Select Hexadecimal and ASCII to restore the default. Whichever mode you last selected in the submenu is used as the default next time you click the View|Hexadecimal item directly.
If you have used View|Split Editor to split the editor in two, then you can select Split Hexadecimal and ASCII in the View|Hexadecimal submenu to have the first half of the editor show only the hexadecimal representation, and the second half of the editor only the ASCII representation. If you didn't split the editor, then the editor shows both the hexadecimal and ASCII representations.
By default, the hexadecimal view groups bytes in blocks of 8 bytes and shows as many blocks of 8 bytes on one row as will fit within the width of EditPad's window. If your binary files use a specific record size, it may be more convenient to display one record on one row, even if that requires horizontal scrolling or leaves blank space. Use Options|Record Size to specify the number of bytes EditPad Pro should display per row in hexadecimal mode.
If your binary files store integer or floating point numbers that are larger than one byte, you can easily edit those numbers in decimal representation using EditPad Pro's Byte Value Editor while you're in hexadecimal mode.
View|Byte Value Editor