Every enhancement of the Apple II computer has been designed to be as compatible as possible with earlier models.

The Apple IIGS has more memory and more features than any of the models that came before it, but those features are implemented in such a way that you can use most of the software developed for earlier machines. Keep in mind, though, that if an application was developed for earlier models of the Apple II, it won't take advantage of the features of later models.

For example, the Apple II Plus keyboard generated only uppercase characters, so applications developed for that model recognize only uppercase characters. You can run Apple II Plus applications on your Apple IIGS, but you have to remember to type everything in uppercase letters. Conversely, if an application is designed to take advantage of Apple IIGS-specific features, it may not work on earlier Apple II's. If compatibility with other Apple II's is important, choose applications that are advertised as compatible with the Apple IIGS, Apple IIc, and Apple IIe.

This chapter summarizes the differences between the various models of the Apple II family so you can anticipate and cope with differences that affect the way software looks and works.

149