Why does this fail?

[David Dick]

The program at the end of this posting produces the following
output when run on the three machines given:

RESULTS--

	ARIX (Motorolo 68020):

	inch returned 'X' (0x58)

	IBM RS/6000:

	inch returned '' (0x0)

	IBM PS/2 (Intel something):

	inch returned 'X' (0x58)

PROGRAM--

    /* intst -- simple inch() test */

    #include <curses.h>
    #include <stdio.h>

    main()
    {
	int ch;

	initscr();
	move(10,10);
	addch('X');
	move(10,10);
	ch = inch();
	endwin();
	printf("inch returned '%c' (0x%0x)\n",ch,ch);
    }