Unless pxsize is set really high (>50), you should run this in Turbo Mode. Draw by clicking and dragging on the screen. Use up and down arrows to scroll up and down. Adjust “pxsize” to change pixel size. Weirdness can be achieved by changing the pixel size after you've already drawn on the screen. Twiddle “lineheight” to adjust terminal line height (in pixels). In the future when this becomes an actual terminal, this variable will affect font size and stuff, but for right now, it just changes the scroll amount.
I think it would be pretty cool to turn this into a TV typewriter of some sort. http://www.catb.org/jargon/html/tv-typewriters.html