This application is a digital stop watch with a 0.1s resolution displaying up to
59 minutes and 59.9 seconds.

The input RD7 is the reset, take High (+5V) to clear the display to 00:00.0 and
Lo (0V) for normal operation.

The input RD6 is the Start/Stop, take High (+5V) to run and Lo (0V) to stop and hold
the current reading on the display.

The checksum of the code is 3EC1, using software application IC-Prog.

Accuracy is dependant on the tolerance of the 4Mhz crystal.  My development model was
within 1s after an hour, using a stopwatch.


