T -90 
A 250 -108  # an arc 250 cogs, 108 degrees to the right
A 250 180   # an arc 250, 180 degrees to the left
*           # let the program to close the path
X
W 0.2       # penwidth 0.2 points
S 0.5
D 250       # disc 250 cogs
H 245       # hole 245, constant
V 0 18 20   # deviation 0, increment of deviation 18 degrees 20 times

R 50        # resolution 50 points per segment
N           # compute how many cycles will be required 
            # to close the spirogram

C 255 0 0  > 0 0 255    5   # colors red -> blue  5 values
+ 0 0 255  > 0 255 0    5   # colors blue-> green 5 values
+ 0 255 0  > 255 255 0  5   # colors green-> yellow 5 values
+ 255 255 0 > 255 0 0   5   # colors yellow-> red 5 values
G 20

D -250     # put the disc "inside" the path
H  245     # same hole, 245, constant   

G 20