In order for electronic books to become popular, it is important that common hardware and software standards be implemented. Hardware may be divided into three categories: portable PCs, organizers, and book readers.
Portable PCs are general-purpose devices, in the sense that they are designed to address a number of different user requirements. None have been specifically designed with electronic books in mind. In some ways this gives them an advantage in the marketplace, since a potential buyer could justify the purchase as being a solution to numerous problems. Compatibility with the wide assortment of DOS or Mac software is also a benefit. However, in order to be usable, they must have a large keyboard, compatible display, hard drive, and other hardware which prevents them from being too small.
In contrast, organizers eschew general operating systems. These gadgets are primarily used as extended desktops with an address book, notepad, calendar, calculator, and other simple tools. Their advantage is their extremely small size. Casio and Sharp are two of the more important developers.
Book readers are designed specifically to support electronic books; any other convenience features are incidental. Examples include the Sony Data Discman and the Digital Book System from Franklin Electronic Publishers.