Brent Hilpert wrote:
  I think you have my question backwards, the question
is what are the
 additional 8 pins (24-pin package I have been advised) being used for on the
 4040, given as Dwight says, that the bus interface is the same. 
All I can say is try to find the real data sheet. Ben.
Pinouts here 
http://intelvsamd.info/Intel_4040.html
Instruction set 
http://www.pastraiser.com/
PS. I don't see anything under bitsavers/intel