Thank you for your suggestions.
There are many different kinds of oscilloscope.
Yes. There are many oscilloscopes which the time/div and volts/div knobs are fixed steps.
However, there are also digital oscilloscopes which the time/div and volts/div knobs can be adjusted continuously.
The above simulation already provide a [b]yoffset[/b] knob for moving the trace vertically.
The purpose for the above simulation is to help user understand how the trace of the oscilloscope was formed.
That is why it provide options for users to select types of X/Y functiona: [b]A sin(wt+B)[/b] or [b]C t +D[/b]
If you need a simulation which is very similar to the one you are using. I will try to create one for you if you can provide a picture of the oscilloscope need to be simulated.