A ROM cartridge, sometimes referred to simply as a cartridge or cart, is a removable enclosure containing read-only memory devices designed to be connected to a consumer electronics device such as a home computer or games console. ROM cartridges can be used to load software such as video games, or other application programs. The cartridge slot could also be used for hardware additions, for example speech synthesis. Some cartridges had battery-backed static random-access memory, allowing a user to save data such as game progress or scores between uses. ROM cartridges allowed the user to rapidly load and access programs and data without the expense of a floppy disk drive, which was an expensive peripheral during the home computer era, and without using slow, sequential, and often unreliable Compact Cassette tape. An advantage for the manufacturer was the relative security of distribution of software in cartridge form, which was difficult for end users to replicate. However, cartridges were expensive to manufacture compared to making a floppy disk or CD-ROM. As disk drives became more common and software expanded beyond the practical limits of ROM size, cartridge slots disappeared from later consoles and computers. Cartridges are still used today with handheld gaming consoles such as Nintendo 3DS and PlayStation Vita.