Write graphics pixels in 16-bit assembly
<p>I'm trying to develop my own very basic operating system for educational purposes. While coding the kernel, I tried to set color to some pixels on screen to make it look better, but I failed.</p>

<p>I used <code>INT 10h</code> with <code>AH = 0CH</code> with video mode <code>13h</code> (320x200 graphics, 256 colors, 1 page) and tried several other modes like <code>01h</code> and <code>03h</code> but they don't work.</p>

<p>This is my complete code:</p>

<pre><code>;set video mode
mov ah, 00h
mov al, 13h

int 10h

;write pixels on screen
mov ah, 0ch
mov bh, 0
mov dx, 5
mov cx, 5
mov al, 0100b

int 10h
</code></pre>

<p>What's wrong with my code?</p>