off clear and the entering of the numbers by enter all the required and computed information is displayed on the lcd 14 during the entry of data and at the appropriate time power from the shaft encoder power switch 16 is applied to the shaft encoder allowing the signals to be processed by the central processing unit again at the appropriate time power is applied via the heart monitor power switch 17 allowing the correct calculations to be made by the processor displaying and keyboard scanning will continue in this manner until the unit is turned off the power is supplied in the form of an unregulated dc to the common regulator and power switch circuit 20 to turn the unit on or off fig9 illustrates the software algorithm a verbal description of fig9 is as follows firstly the start switch is operated to bring power to the equipment the software clears all variable memory space and sets the various memories to a default condition it displays messages a copyright message and the wording 34 ft100 plus v1 0 34 the next request is to request the user to enter the mode 1 to 5 upon entering the mode and depending on the selected mode the request is then made to enter age after the age has been entered the time of the exercise is also entered if no time is given that is if the user elects to exercise for a variable time.