org 0x7c00

main:
        mov ah, 0
        mov al, 0x13 ; 320x200x8
        int 0x10
        
        mov ax, 0 ; x
        mov bx, 0 ; y
        mov cl, 0 ; color
.horiz_loop:
        call putpixel
        inc ax
        inc cl
        cmp ax, 16
        jl .horiz_loop
        mov ax, 0
        inc bx
        cmp bx, 16
        jl .horiz_loop

        cli
.loop:
        hlt
        jmp .loop

putpixel:
        push ax
        push bx
        push es
        push di

        imul bx, 320
        add bx, ax
        mov di, bx
        mov ax, 0xA000
        mov es, ax
        mov [es:di], cl
        
        pop di
        pop es
        pop bx
        pop ax

        ret

times 510 - ($-$$) db 0
db 0x55, 0xaa