#include <stdio.h>
#include <conio.h>

void main()
{
    int c1, c2;
    while (!kbhit());
    c1 = getch();
    if (c1 == 0)
    {
        c2 = getch(); 
        printf("c1=%#02x c2=%#02x",c1, c2);
    }
    else
        printf("c1=%#02x",c1);    
}

/*
nonprintable characters:
                c1      c2
    F1          00      3b
    F2          00      3c
    F3          00      3d
    F4          00      3e
    F5          00      3f
    F6          00      40
    F7          00      41
    F8          00      42
    F9          00      43
    F10         00      44
    F11         --      --
    F12         --      -- 
    ESC         1b      --
    Enter       0d      --
    PrtScr      --      --
    ScrLck      --      --
    Pause       --      --
    up          00      48   shift-up
    down        00      50   shift-down
    left        00      4b   shift-left
    right       00      4d   shift-right
    ctrl-up     --      --
    ctrl-down   --      --
    ctrl-left   00      73
    ctrl-right  00      74
    shift-a     41      --
    a           61      --
    ctrl-a      01      --
*/