>Generating a Random Number
>
>             copyright, Peter H. Anderson, Dept of Electrical
>Enginnering,
>             Morgan State University, Baltimore, MD 21239, August 9, '97
>


This is a broken implementation of a PN generator. The need for a trap for
the all zeroes condition tells you that it's broken. In a good
implementation, unless you start it at all zero, it will never get there on
it's own.
The hack to keep it from locking, also shortens the sequence. :(