The SillyDog Archive that James referred to is
http://sillydog.org/narchive/.
Look at both areas:
- top section, center column;
- and scroll down to Communicator 4.5 ~ 4.8.
Both indicate a minimum of OS 8.1.
Just click on the text that is underlined.
UserAgent: Mozilla/5.0 (Windows; U; Win95; en-US; rv:1.8.1b1) Gecko/20060710 Firefox/2.0b1