.MODEL SMALL
        .DATA
MESSAGE DB "You pressed:$"
        .CODE
        .STARTUP

        ;Read the keys with echo until ESC key is pressed
        ;Print a message each time
LABEL1: mov ah, 9       ; Select function 9, print a string
        mov dx, OFFSET MESSAGE
        int 21h         ; Interrupt 21h (DOS functions)

        ;Read the key (BIOS)

WAITKEY: mov ah, 01      ; Select function 1, check the buffer
        int 16h         ; Interrupt 16h (BIOS functions)
        ;If flag Z is set, the keyboard buffer is empty
        JZ WAITKEY

        mov ah, 0       ; Select function 0, read the first key from the buffer
        int 16h

        cmp al,1BH      ; Compare to ESC code (ASCII)
        jne LABEL1      ; If not ESC - continue
        .EXIT
        END