The original 8-inch floppy disk had the capacity of 3,000 punched cards. Because many companies still relied on punched card systems for data entry, IBM adapted its punched card data entry machines so the operators could easily shift from loading data on paper cards to putting it on disks.
In 1977, Apple introduced the Apple II, which came with two 5¼-inch floppy drives, which were supplied by Shugart Associates, a company started by IBMers. The first IBM PC, introduced in 1981, was available with two floppy drives. Users typically loaded an application in one drive and stored data on a diskette in the other. In 1984, IBM introduced the high-density floppy disk for the PC; it stored 1.2 megabytes of data — sizable at the time. Two years later, IBM introduced the 3½-inch floppy disk that featured 1.44 megabytes of storage space and a plastic case surrounding the internal disk, a format that became the mainstay of computing in the 1990s. The 3½-inch disks were more compact and had higher storage capacity, and the rigid case provided better protection.
The advent of the floppy was a great convenience for individual users, but it also marked a true step forward in the structure of the IT industry. Up until the late 1970s, most software applications were written by the PC owners themselves. Now companies could write programs and sell them on disks through the mail or in stores. “It made it possible to have a software industry,” said Lee Felsenstein, a pioneer of the PC industry who designed the Osborne 1, the first mass-produced portable computer. Before networks became widely available for PCs, people used floppies to share programs and data with each other — calling it the “sneakernet.”