'H' goes to the beginning of the line, 'L' to the end. 'w' moves forward by a word. 'W' moves backward by a word. 'I', 'F' and 'E' invoke the corresponding command from the Block Editor (B100). Refer to documentation there. 'X' deletes "modifier" characters following cursor. 'R' goes into replace mode at current cursor position. Following keystrokes replace current character and advance cursor. Press return to return to normal mode.