I would like to study this project with the whole block diagram and the components used.

You can create following 8085 project using 8255

1. Traffic Light Control System
2. Controlling The Stepper Motor
3. Temperature Control System
4. Blinking LEDs In Circular Pattern

Out of these four projects, blinking LEDs in circular pattern is very simple as hardware required to create this project is minimum and coding is also very easy....

Temperature Control System needs sensing circuitry, analog to digital converter and circuit required to control the controller making project quite difficult.

Project On Controlling The Stepper Motor is easy. Its coding is the simplest but it obviously need one working stepper motor.

Traffic Light Control System is also a good project to opt for but it requires around 12 transistors and 12 relays.