Designed with an STK600, the LCD controller uses the push buttons to toggle bits for controlling a character LCD.
The LCD should be connected to Port A with the corresponding bits:
PA0 = DB4 PA1 = DB5 PA2 = DB6 PA3 = DB7 PA4 = RS PA5 = E Ground = RW
Switches 0 - 6 are the bits to be output to the LCD and are indicated by their corresponding LEDs. Switch 7 signals to the program to output to the LCD.