Your addresses are for the BIOS data area and the video memory. The BIOS data area has been used in the early days of PCs during system boot.
But with actual operating systems these data are no longer available. The page
Memory Map (x86) - OSDev Wiki[
^] contains a good description of these memory areas.
While it is possible to access these data when using DOS, it is better to use the DOS interrupts (INT 21h, e.g. function 01 to read a character from stdin) or the BIOS interrupts (e.g. INT 09h for keyboard).
When not using DOS and you don't want to use libraries you must use API functions of the operating system because modern OS does not allow direct hardware access. With Windows for example use the
ReadConsoleInput function (Windows)[
^].