.model
.stack 100h
    max_cols EQU 720
    max_rows EQU 400
.code
start:

    ; init video mode
    mov ax,0012h
    int 10h

    call fill_screen

    ;mov al,02h
    ;mov ah,0ch
    ;mov al, 1h
    ;int 10h



    jmp end_program


fill_screen:
    pop bx      ;save ret adress
    mov dx, 1
loop_row:
    mov cx, 1
loop_col:
    ; body here

    ;call print_coords
    mov al, dl
    xor al, cl
    call fill_pixel

    ; end body
    inc cx
    cmp cx, max_cols
    jne loop_col

    inc dx
    cmp dx, max_rows
    jne loop_row


    push bx
    ret

end_program:
    mov ah, 4Ch
    int 21h

print_coords:
    push dx
    push cx     ;save registers in stack
    push ax

    mov ah, 2   ;print dl
    or dl, 30h
    int 21h

    mov dl, 'x'
    int 21h

    mov dl, cl  ;print cl
    or dl, 30h
    int 21h

    mov dl, 0Ah ;  LF
    int 21h

    mov dl, 0Dh ;  CR
    int 21h

    pop ax
    pop cx
    pop dx
    ret

fill_pixel:   ;fills pixel in col cx and row dx with color in AL

    mov ah, 0Ch
    int 10h
    ret



end start