Later versions (1.05, 1.10) added support for USB hubs, better error handling, and even a curses-based interactive mode. So why remember 1.02?
The software will begin the conversion process. During this time, it creates the split files and updates the "ul.cfg" file, which acts as the directory for your PS2. Once the process is finished, you can safely eject the drive and plug it into your console. Common Troubleshooting usbutil ver 1.02