🚀 go-pugleaf

In article <5758@lindy.Stanford.EDU> liz@ucscb.UCSC.EDU (Space Cadet) writes:
>
>     I am designing a shift register based psuedo-random number generator.
>I have a list of feedback connections (from CMOS Cookbook) for lengths up
>to 31, but may need a length up to 36 (no, 2G random numbers aren't enough
>for me :-)
>

Add the following to your list:

     # of FF     Feedback       Period
     31          3,31        2,147,483,647
     33          13,33       8,589,934,591
     35          2,35       34,359,738,367
     36          11,36      68,719,476,735

Most longer sequences are linear combinations of smaller sequences.  The
book by Samuel Golomb on "Shift Register Sequences" is considered the 
classic in this field.  The mathematics in the book allows you to calculate
sequences of larger registers and more importantly, how to generate very
long sequences for a number of smaller registers.


Dennis