| We introduce the fundamental building blocks of 
            digital computers.  We discuss truth tables as a way both of describing 
            an existing circuit and of specifying a circuit to be built.  e introduce circuits whose output values depend only 
            on a combination of the input values.  We explain how to describe circuits as algebraic 
            formulae and how to manipulate those formulae with algebraic laws.  A particular combinatorial circuit so commonly used 
            that we discuss it separately.  A particular combinatorial circuit so commonly used 
            that we discuss it separately. A particular combinatorial circuit so commonly used 
            that we discuss it separately.  In this section, we introduce the fundamentals of 
            binary arithmetic and representation of numbers.  We show different circuits for binary arithmetic and 
            explain trade-offs between speed and number of gates.  Flip-flops are the basic elements of sequential 
            circuits, the way gates are the basic elements of combinatorial 
            circuits.  We discuss state tables as a way both of describing 
            an existing sequential circuit and as a way of specifying a 
            sequential circuit to be built.  We introduce circuits whose output values depend not 
            only on the inputs, but also on previous input and output values.  A register is a particularly simple sequential 
            circuit that can be instructed to store its input values 
            indefinitely.  A counter is a another particularly simple 
            sequential circuit that normally increments its stored value for 
            each clock pulse.  We show how to build a circuit for binary 
            multiplication.  Tri-state logic circuits represent a pragmatic 
            solution to some problems of circuit complexity. With tri-state logic, we can use a bus to transport 
            data.  While memories are clearly sequential circuits, they 
            have a special structure that makes it interesting to look at them 
            separately.  A read-only memory is nothing more than a 
            combinatorial circuit, but often built as a memory.  |