Um, it's gone, but it was so old I doubt it still worked correctly anymore.
The basics were change the angle with the left or right buttons, and setting the position with trig.
Where x, and y were the center of the layout, and distance would have been half the layout width.
right add to angle, left subtract.
Im not sure we had anglelerp() back then, but it would work well for it.
Tempest was a bit different though, as I call it didn't iterate all 360 angles, it would jump from segment to segment.
So basically 360/ the number of segments gives you the number to add.