I have a PSR-800. Updating the database on the PSR-800 does require software. However, GRE provides the software, which is called EZ-Scan Digital, on CD and includes it with the scanner. I believe it can also be downloaded from their support website.
According to the Radio Shack website the Pro-18 also includes a CD-ROM with PC software. I am guessing this would be similar to the EZ-Scan Digital software.