I've included the following examples:

- Counter.hs
     The Chalk HelloWorld - a simple circuit that counts the number of clock
     cycles since its argument signal was True.

- ALU.hs
     Simple ALU with two multipliers. I

- ALUSym.hs
     Variation of the ALU.hs, uses symbolic simulation to build an explicit
     the constraints and costss

- And.hs  
     Uses the join of the (a,Int) monad to show how the cost may depend on the
     input of the circuit.

- Sham.hs, ShamII.hs, ShamIII.hs, ShamIV.hs, ShamV.hs 
     A series of example microprocessors taken from "Specifying superscalar 
     microprocessors in Hawk". It starts out quite simple (ALU and register
     file), but the last version is a pipelined toy MIPS mipcroprocessor
     inspired by the Hennessy and Patterson book.

- Fifo.hs 
     Not completely stupid implementation of queues. Used in ShamV.hs.

- Graph.hs
     Shows how to call the graph visualisation functions.

- RegFile.hs
     Shows how to measure the activity of a circuit (in this case, Sham's 
    register file.)