This pack lets you draw complicated things on the screen with a range of effects which can be assessed from the ten function keys. You draw by selecting a direction using the cursor keys or a combination of them, then select a velocity using the number keys from 0-9. Here are what the functions can do:

f0 ... clears the screen.
f1 ... lets you change the foreground and background colours to any of the sixteen available.
f2 ... lets you define the width of your nib.
f3 ... is a very good effect which makes polygons of any number of sides from triangles to circles. There are also two radii involved so you can create ellipses and rectangles and really any shape you want. Also, you can use a polygon as a nib by moving the cursor and pressing the Space Bar to repeat the figure.
f4 ... is similar to f3 but it draws spheres with lines of latitudes and longitude with any radii, so you can get an oblong spheroid if you like.
f5 ... is exactly the same as f3 in that you are asked to give information regarding to a polygon, but the difference is that you move the cursor to another point away from the centre of the polygon and it will draw lines from that point to the vertexes of the polygon to create a prism or cone in the case of a circle.
f6 ... lets you create any mesh at any part of the screen.
f7 ... gives you a set of preset horizon lines on the screen.
f8 ... lets you use some text on the screen either to table things or to use the letters as a kind of strange-shaped nib.
f9 ... enables you to stop drawing.

All in all, this is a program which has many advantages and helps you to design complicated and beautiful patterns. However, some of the GCOC functions could have been employed to greater effect.