Define KEY_MIN and use it in kb.c.

src/hci/mucurses/kb.c

 	c = _wgetc( win );
 
 	if ( m_echo ) {
-		if ( c >= 0401 && c <= 0633 ) {
+		if ( c >= KEY_MIN ) {
 			switch(c) {
 			case KEY_LEFT :
 			case KEY_BACKSPACE :
 			_wcursback( win );
 			wdelch( win );
 		} else {
-			if ( c >= 0401 && c <= 0633 ) {
+			if ( c >= KEY_MIN ) {
 				switch(c) {
 				case KEY_LEFT :
 				case KEY_BACKSPACE :

src/include/curses.h

 /*
  * KEY code constants
  */
+#define KEY_MIN		0401		/**< Minimum special key */
 #define KEY_BREAK	0401		/**< Break key */
 #define KEY_DOWN	0402		/**< down-arrow key */
 #define KEY_UP		0403		/**< up-arrow key */