DS1621 pc thermometer

[gamelektro]

I look the project in Electronic-Lab.com it's about DS1621 pc thermometer. 
http://www.electronics-lab.com/projects/pc/010/index.html

i need to know full explanation about the schematic, please tell me how ds1621 pc thermometer  work.  i didn't get understand what  function the diode zener in the schematic,  please tell me how it work the voltage regulator in the schematic. how the pc can read the data from the IC? i know about I2C but i dont understand about this project, The Explanation to little , is this project ds1621 really work?...I want to try to make this project.
Please Help me... 

 

[audioguru2]

I look the project in Electronic-Lab.com it's about DS1621 pc thermometer.