not_my_default_bootloader/light.asm

[org 0x7000]

start:
    mov [bootdev], dl
    mov ah, 06h    ; Scroll up function
    xor al, al     ; Clear entire screen
    xor cx, cx     ; Upper left corner CH=row, CL=column
    mov dx, 184FH  ; lower right corner DH=row, DL=column
    mov bh, 4Fh    ; YellowOnBlue
    int 10H         ; execute interrupt

    mov     al, 182         ; meaning that we're about to load
    out     43h, al         ; prepare speaker for output

    mov     ax, 2153        ; frequency countdown value is stored in ax. It is calculated by
    out     42h, al         ; Output low byte.
    mov     al, ah          ; Output high byte.
    out     42h, al

    in      al, 61h
    or      al, 00000011b
    out     61h, al         ; Send the new value
;    mov     bx, 200          ; Pause for duration of note.


    mov ah, 06h    ; Scroll up function
    xor al, al     ; Clear entire screen
    xor cx, cx     ; Upper left corner CH=row, CL=column
    mov dx, 184FH  ; lower right corner DH=row, DL=column
    mov bh, 12h    ; YellowOnBlue
    int 10H         ; execute interrupt
mov al, 0
mov ah, 86h
mov cx, 1
mov dx, 200
int 15h
    mov ah, 06h    ; Scroll up function
    xor al, al     ; Clear entire screen
    xor cx, cx     ; Upper left corner CH=row, CL=column
    mov dx, 184FH  ; lower right corner DH=row, DL=column
    mov bh, 2Bh    ; YellowOnBlue
    int 10H         ; execute interrupt
mov al, 0
mov ah, 86h
mov cx, 1
mov dx, 200
int 15h
    mov ah, 06h    ; Scroll up function
    xor al, al     ; Clear entire screen
    xor cx, cx     ; Upper left corner CH=row, CL=column
    mov dx, 184FH  ; lower right corner DH=row, DL=column
    mov bh, 3Fh    ; YellowOnBlue
    int 10H         ; execute interrupt
mov al, 0
mov ah, 86h
mov cx, 1
mov dx, 200
int 15h


;.pause1:
;        mov     cx, 65535
;.pause2:
;        dec     cx
;        jne     .pause2
;        dec     bx
;        jne     .pause1
        in      al, 61h         ; Turn off note (get value from
                                ;  port 61h).
        and     al, 11111100b   ; Reset bits 1 and 0.
        out     61h, al         ; Send new value.


mov al, 0
mov ah, 86h
mov cx, 1
mov dx, 200
int 15h



waitforkey:
        mov ah, 0x00
        int 0x16
        cmp ah, 01h
        je exit
	jmp waitforkey

exit:
        in      al, 61h         ; Turn off note (get value from
                                ;  port 61h).
        and     al, 11111100b   ; Reset bits 1 and 0.
        out     61h, al         ; Send new value.
	mov dl, [bootdev]
	jmp 0x0:0x1000

bootdev         db 0x80         ; Boot device number