This file describes several digital circuits which use some of CircuitMaker's
animated components.

Circuit                     Description and Operation
-------                     -------------------------
4X4.CIR         This file contains a circuit that will decode a 4x4 switch
                matrix. When this circuit is simulated, the Hex Display
                will indicate the key that is currently selected. To select
                a different key, simply click on it.

STEPPER.CIR     This file contains a circuit that demonstrates the operation
                of a simulated stepper motor. The simulated stepper motor can
                be connected in unipolar or bipolar mode and can be driven in
                full steps or half steps.

MUX7SEG.CIR     This file contains a circuit that demonstrates the principle
                of multiplexing. It contains a common-anode and a common-
                cathode 7-segment display which share the same data lines.
                When this circuit is simulated, the 7-segment displays are
                driven one at a time. To reduce flickering, the delay value
                associated with each 7-segment display can be increased to
                simulate a higher multiplex frequency.

CARS.CIR        This file contains a circuit that will time a simulated
                pine-wood derby car race. To start the race, click on the
                start button. To run the same race again, click on each
                reset button and then the start button. To run a different
                race, click on the circuit reset icon and then the start
                button.
                
ROCKET.CIR      This file contains a circuit that will set off a simulated
                model rocket. When run, this circuit will count begin by
                counting down from 9. When the count goes below the warning
                count, a buzzer will sound. Then, if the arm switch is on,
                when the count reaches 0 the rocket will take off.
                                
ALARM.CIR       This file contains two simple examples of burglar alarm
                circuits. The open-circuit burglar alarm demonstrates the
                principles associated with logical "OR" operations and
                parallel circuits while the closed-circuit burglar alarm 
                demonstrates the principles associated with logical "AND"
                operations and series circuits.
                
                The windows in these circuits can be opened and closed,
                and the switches can be toggled by clicking on them.
                
                When the simulator is running, the alarm buzzer will go off
                if the alarm is enabled and one or more of the windows are
                opened.
                
ALARM1.CIR      This file contains an open-circuit burglar alarm which has
                an exit delay and latched alarm. The exit delay portion of
                the circuit causes a delay to occur between the time the
                alarm is enabled and the alarm can be set off. In a real
                burglar alarm this function allows a person to enable the
                alarm and exit without setting off the alarm.
                
                When the alarm has been set off, the latched alarm portion
                of the circuit prevents the buzzer from turning off until
                the reset button is pressed. In a real alarm, this function
                prevents the burglar from turning the alarm off.
                                
                The exit delay in this circuit is set by selecting a Hex Key
                by clicking and entering a hex number by pressing 0-9 or A-F
                on the keyboard.
                
ALARM2.CIR      This file contains an open-circuit burglar alarm which has an
                exit delay, latched alarm, and an entry delay. The entry delay
                prevents the buzzer from immediately going off when the alarm
                in triggered. In a real burglar alarm, this function allows a
                person to enter the area protected by an armed burglar alarm
                and turn it off before it sounds an alarm.
                
ALARM3.CIR      This file contains an open-circuit burglar alarm which has an
                entry delay, exit delay, latched alarm, and an reset lock. The
                reset lock will turn the burglar alarm off when the correct
                combination is entered. In a real burglar alarm, this function
                will prevent anyone that does not know the correct combination
                from resetting or turning off the burglar alarm.