An oscilloscope in VB

In automation problems one of the most important requirement is the signal and states representation. For the analog signals the oscilloscope (analog or digital) is the preferred solution.
How to show our A/D acquisitions on the screen of a PC?
The screen refresh is the problem.
With the Windows API <GDI32> and the <BitBlt> method is simple store and shift the video memory realizing the oscilloscope traces update.
The applied solution is:

• run an infinite sampling loop;
• get a new sample;
• use a little slice of the video memory to draw the sample;
• shift of some pixel the window.

This kind of solution is valid for slow signals (max 500Hz).