title: How to set the system time using assembly 8086 with dosbox?
body: <p>I wish to set the system time, and get the time for display. i have successfully get he system time with the following code</p>
  
  <pre><code>mov ah,2ch              ;get time
  int 21h                 ;ch = hr, cl = min, dh = sec
  </code></pre>
  
  <p>but i cannot set the system time, by following 2 methods</p>
  
  <pre><code>mov ah,03h
  
  mov ch,hr(in bcd)
  mov cl,mm(in bcd)
  mov dh,sec(in bcd)
  mov dl,am_pm
  
  int 1ah 
  </code></pre>
  
  <p>and</p>
  
  <pre><code>mov ah,2dh
  mov ch,hr
  mov cl,mm
  mov dh,sec
  int 21h
  </code></pre>