Multiple Clocks


This dialog-based application displays several different styles of clocks: analog, binary, decimal, and nixie.


The Nixie tube was used in electronic instruments mainly in the 1960s thru 1980s. It is a neon-filled vacumn tube with 10 elements that can make the neon glow when any one element is grounded. The tube has a common anode with approximately 175 volts DC applied to it. I think it makes a cool clock.

Using the Code

Several methods used in this code are borrowed from other programmers, some from this site (see Credits). The heart of the binary clock is the _itoa(nTime, ibuff, 2); function, where nTime is any integer contaning the hour, minute, or second. ibuff is a char buffer and the 2 is a base, in this case, binary.

Here is the code to display a simple Decimal clock in the Windows Title Bar.

void CMultiClockDlg::DisplayDecimal()
   // Get the current time
   CTime time  = CTime::GetCurrentTime();
   int nSecond = time.GetSecond();
   int nMinute = time.GetMinute();
   int nHour   = time.GetHour();
   if (nHour > 12)
      nHour -= 12;
   CString szStr;
   szStr.Format("MultiClock - %.2d:%.2d:%.2d", nHour, nMinute, nSecond);
   ::SetWindowText(m_hWnd, szStr);

Points of Interest

The Binary display is grouped: 4 bits for the hour, and 6 bits for the minutes and seconds. I did this because the hour can only be "01" thru "C" and the minutes/seconds "00" thru "3B". The nixie clock uses bitmaps (45X64) for each digit; they are diplayed by calling:

void CMultiClockDlg::FormatTm(CDC *pDC, int nTime, int nPos)
   int x, y;
   x = 8 +(m_bmp.GetWidth() * nPos);
   y = 8;
   switch (nTime)
      case 0:
         m_bmp.DrawDIB(pDC, x, y);

One thing I found when writing this code was this: DO NOT USE CDC *pDC = GetDC(); in a loop without using RelaseDC(pDC); My first version would run for 15 to 20 minutes and crash because GetDC() uses 4 bytes of memory every time it is called.


ClockCtrl—The Analog Clock
Author: P.J. Naughter

Dib256—Load Resource/Paint Bitmap
Author: Jorg Konig


Version 1.0
Any comments or suggestions are welcome.



  • There are no comments yet. Be the first to comment!

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Essential Insights for Successful Cloud Migration and Management Whether you're planning your cloud migration strategy or already in the cloud, making accurate cloud decisions requires a deep analytical approach. This paper discusses the main objectives to achieve, top questions to ask, and the analytics you need at each stage of your cloud journey. You'll learn: How to identify which cloud provider will provide the best cost and performance benefits for your organization How to determine which applications …

  • The open source cloud computing project OpenStack has come a long way since NASA and Rackspace launched it in 2010. Backed by leading technology infrastructure providers including Cisco, Dell, EMC, HP, IBM, Intel, and VMware, OpenStack underpins significant workloads at an increasingly diverse set of organizations, including BWM, CERN, Comcast, eBay, and Wal-Mart. For CIOs engaged in broader programs to win, serve, and retain customers -- and refocus business technology (BT) spend -- a planned and pragmatic …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date