What's the most elegant way to monitor key presses in RM?

Hi people!
The idea is simple... I want my program to execute until ESC is pressed.
I installed INT 1Ch handler:

Code:

mov si, 001Ch*4
    mov eax, [si]
    mov [int1C], eax
    cli
    mov word [si], int_1C
    mov [si+2], bx
    sti

The handler itself is

Code:

int_1C:
    push ds
    push bx
    xor bx, bx
    mov ds, bx
    mov bl, [041Ch]
    add bx, 03FFh           ;start of kbd_buf + 1
  @@:
    mov al, [bx]
    mov bl, [0480h]
    mov bh, bl
    mov word [041Ah], bx
    cmp al, key_scancode_esc
    jz .esc_pressed
    pop bx
    pop ds
    iret
  .esc_pressed:
    pop bx
    pop ds
    push ds
    push cancel
    iret

it checks if ESC was pressed (by scan code in kbd buffer) and if so, jumps to label cancel:

Code:

cancel:;+
    push szHaltedByUser_Error
    cli
    mov eax, [int1C]
    mov [001Ch*4], eax
    sti
    mov dx, 140Fh                ;just output some messages like
    call set_cursor                 ; press ESC to continue or X to reboot
    mov si, szHalted
    call show_msg
    pop si
    call show_msg
    mov si, szEsc2Load
    call show_msg
  .wait_keypress:
    xor ax, ax
    int 16h
    cmp al, 0Dh
    jz boot_next_device
    cmp al, 1Bh
    jz cold_reboot
    jmp .wait_keypress

this doesn't work neither in bochs nor in wmware.
I can't understand where the problem is. It outputs only one char of the first string, then stuns.
Is there any more elegant way to monitor if a key was pressed in background? This code is used in bootloader. Thanks!

int_9: push ax ;save AX 'cause it may be in use somewhere in al, 60h cmp al, 81h ;break code for ESC jnz @f add sp, 4 push cancel mov al, [041Ah] ;clear kbd buffer because Int 16h Fn 1 will mov [041Ch], al ;return previous keypress immediately sub sp, 2 @@: pop ax jmp dword [cs:int9] ;execute default INT 9 handler. CS is used because ;I use the same segment for code and data