Speed   = 8              ...if Voltage > 250
          6              ...if Radius < 200
          2 + Random(3)  ...otherwise, i.e. random between 2 and 4
Heading = Old_heading - 10 + Random(21)
                         ...i.e. change by +/- 10 degrees
This is a testing version.
It may be incomplete, and have more bugs (or features) than the public live version at planetscentral.com.